Common use of Historical Clause in Contracts

Historical. 1994 1995 1996 1997 ---- ---- ---- ---- Revenues $ 42,142 $ 91,714 $ 123,199 $ 198,900 % increase in Revenues 117.6% 34.3% 61.4% Cost of Revenues 21,759 46,384 62,900 115,747 --------------------------------------------------- Gross Profit $ 20,383 $ 45,330 $ 60,299 $ 83,153 Gross Profit % 48.4% 49.4% 48.9% 41.8% Operating Expenses: Corporate G&A NA NA NA NA Goodwill Amortization and Other Expenses NA NA NA NA Research & Development expenses 4,149 9,036 12,910 17,303 ▇▇▇▇▇▇▇, General & Administrative Expenses 12,136 28,501 36,493 53,182 --------------------------------------------------- Total Operating Expenses $ 16,285 $ 37,537 $ 49,403 $ 70,485 --------------------------------------------------- Earnings Before Interest and Taxes 4,098 7,793 10,896 12,668 EBIT Margin 9.7% 8.5% 8.8% 6.4% Interest Income 226 820 935 692 Interest (expense) (114) (707) (773) (4,217) Other Expense, Net -- -- -- -- Restructuring Costs -- -- (171) 1,257 --------------------------------------------------- Total Other Income (Expense) 112 113 (9) (2,268) --------------------------------------------------- Income Before Taxes 4,210 7,906 10,887 10,400 Provision (Credit) for Income Taxes 1,842 3,312 4,270 4,552 --------------------------------------------------- Net Income $ 2,368 $ 4,594 $ 6,617 $ 5,848 =================================================== Basic Earnings Per Share $ 0.25 $ 0.41 $ 0.53 $ 0.40 Depreciation and Amortization 1,273 3,720 4,493 6,615 --------------------------------------------------- EBITDA 5,371 11,513 15,389 19,283 =================================================== ▇▇▇▇▇▇ ▇▇▇▇▇▇ 12.7% 12.6% 12.5% 9.7%

Historical. 1994 1995 1996 1997 1998 1Q1999 1Q1998 LTM ---- ---- ---- ---- ------ ------ --- Revenues $ 42,142 191,017 $ 91,714 41,874 $ 123,199 53,067 $ 198,900 179,824 % increase in Revenues 117.6% 34.3% 61.4% (4.0%) NA NA NA Cost of Revenues 21,759 46,384 62,900 115,747 110,915 25,111 30,397 105,629 --------------------------------------------------- Gross Profit $ 20,383 80,103 $ 45,330 16,763 $ 60,299 22,670 $ 83,153 74,195 Gross Profit % 48.441.9% 49.440.0% 48.942.7% 41.841.3% Operating Expenses: Corporate G&A NA NA NA NA 1,528 335 425 1,439 Goodwill Amortization and Other Expenses NA NA NA NA 3,538 1,065 463 4,140 Research & Development expenses 4,149 9,036 12,910 17,303 ▇▇▇▇▇▇▇16,298 3,771 4,513 15,555 Selling, General & Administrative Expenses 12,136 28,501 36,493 53,182 48,474 10,191 12,890 45,776 --------------------------------------------------- Total Operating Expenses $ 16,285 69,839 $ 37,537 15,362 $ 49,403 18,291 $ 70,485 66,910 --------------------------------------------------- Earnings Before Interest and Taxes 4,098 7,793 10,896 12,668 10,264 1,401 4,379 7,286 EBIT Margin 9.75.4% 8.53.3% 8.88.3% 6.44.1% Interest Income 226 820 935 692 1,333 186 325 1,194 Interest (expense) (1144,337) (707822) (7731,191) (4,2173,968) Other Expense, Net 713 -- -- -- -- 713 Restructuring Costs -- (4,320) (758) -- (1715,078) 1,257 --------------------------------------------------- Total Other Income (Expense) 112 113 (96,611) (2,2681,394) (866) (7,138) --------------------------------------------------- Income Before Taxes 4,210 7,906 10,887 10,400 3,653 7 3,513 147 Provision (Credit) for Income Taxes 1,842 3,312 4,270 4,552 1,828 4 1,440 391 --------------------------------------------------- Net Income $ 2,368 1,825 $ 4,594 4 $ 6,617 2,073 ($ 5,848 244) =================================================== Basic Earnings Per Share $ 0.25 0.12 $ 0.41 0.00 $ 0.53 0.14 ($ 0.40 0.01) Depreciation and Amortization 1,273 3,720 4,493 6,615 8,682 1,929 1,814 8,797 --------------------------------------------------- EBITDA 5,371 11,513 15,389 19,283 18,946 3,330 6,193 16,083 =================================================== ▇▇▇▇▇▇ ▇▇▇▇▇▇ 12.79.9% 12.68.0% 12.511.7% 9.78.9% --------------------------------------------------- Projected ----------------------------------------------------------------- 1999 2000 2001 2002 2003 ---- ---- ---- ---- ---- Revenues $ 188,102 $ 209,659 $ 229,437 $ 251,819 $ 285,080 % increase in Revenues (1.5%) 11.5% 9.4% 9.8% 13.2% Cost of Revenues 102,135 111,966 121,630 132,314 149,500 ----------------------------------------------------------------- Gross Profit $ 85,967 $ 97,693 $ 107,807 $ 119,505 $ 135,580 Gross Profit % 45.7% 46.6% 47.0% 47.5% 47.6% Operating Expenses: Corporate G&A 1,504 1,677 1,835 2,015 2,281 Goodwill Amortization and Other Expenses 3,984 4,210 4,209 4,491 4,533 Research & Development expenses 16,892 16,898 17,992 19,200 21,098 ▇▇▇▇▇▇▇, General & Administrative Expenses 43,708 45,586 49,009 52,775 58,182 ----------------------------------------------------------------- Total Operating Expenses $ 66,088 $ 68,371 $ 73,045 $ 78,481 $ 86,094 ----------------------------------------------------------------- Earnings Before Interest and Taxes 19,879 29,322 34,762 41,024 49,486 EBIT Margin 10.6% 14.0% 15.2% 16.3% 17.4% Interest Income 500 482 452 452 452 Interest (expense) (4,100) (4,100) (4,100) (4,100) (4,100) Other Expense, Net -- -- -- -- -- Restructuring Costs (1,055) -- -- -- -- ----------------------------------------------------------------- Total Other Income (Expense) (4,655) (3,618) (3,648) (3,648) (3,648) ----------------------------------------------------------------- Income Before Taxes 15,224 25,704 31,114 37,376 45,838 Provision (Credit) for Income Taxes 4,872 9,145 11,364 13,931 17,400 ----------------------------------------------------------------- Net Income $ 10,352 $ 16,559 $ 19,750 $ 23,445 $ 28,438 ================================================================= Basic Earnings Per Share $ 0.67 $ 1.08 $ 1.28 $ 1.52 $ 1.85 Depreciation and Amortization 12,449 7,417 7,111 7,101 7,218 ----------------------------------------------------------------- EBITDA 32,328 36,739 41,873 48,125 56,704 ================================================================= ▇▇▇▇▇▇ ▇▇▇▇▇▇ 17.2% 17.5% 18.3% 19.1% 19.9%

Historical. 1994 1995 1996 1997 1998 1Q1999 1Q1998 LTM ---- ---- ---- ---- ---- ------ ------ --- Revenues $ 42,142 $ 91,714 $ 123,199 $ 198,900 100.0% increase in Revenues 117.6100.0% 34.3100.0% 61.4100.0% 100.0% 100.0% 100.0% 100.0% Cost of Revenues 21,759 46,384 62,900 115,747 --------------------------------------------------- 51.6% 50.6% 51.1% 58.2% 58.1% 60.0% 57.3% 58.7% ---------------------------------------------------------------------------- Gross Profit $ 20,383 $ 45,330 $ 60,299 $ 83,153 Gross Profit % 48.4% 49.4% 48.9% 41.8% 41.9% 40.0% 42.7% 41.3% Operating Expenses: Corporate G&A NA NA NA NA Goodwill 0.8% 0.8% 0.8% 0.8% Amortization and Other Expenses NA NA NA NA 1.9% 2.5% 0.9% 2.3% Research & Development expenses 4,149 9,036 12,910 17,303 ▇▇▇▇▇▇▇Expenses 9.8% 9.9% 10.5% 8.7% 8.5% 9.0% 8.5% 8.7% Selling, General & Administrative Expenses 12,136 28,501 36,493 53,182 --------------------------------------------------- 28.8% 31.1% 29.6% 26.7% 25.4% 24.3% 24.3% 25.5% Total Operating Expenses $ 16,285 $ 37,537 $ 49,403 $ 70,485 --------------------------------------------------- 38.6% 40.9% 40.1% 35.4% 36.6% 36.7% 34.5% 37.2% ---------------------------------------------------------------------------- Earnings Before Interest and Taxes 4,098 7,793 10,896 12,668 EBIT Margin 9.7% 8.5% 8.8% 6.4% 5.4% 3.3% 8.3% 4.1% Interest Income 226 820 935 692 0.5% 0.9% 0.8% 0.3% 0.7% 0.4% 0.6% 0.7% Interest (expense) (1140.3%) (7070.8%) (7730.6%) (4,2172.1%) (2.3%) (2.0%) (2.2%) (2.2%) Other Expense, Net -- -- -- -- 0.0% 0.0% 0.0% 0.0% 0.4% 0.0% 0.0% 0.4% Restructuring Costs -- -- 0.0% 0.0% (1710.1%) 1,257 --------------------------------------------------- 0.6% (2.3%) (1.8%) 0.0% (2.8%) ---------------------------------------------------------------------------- Total Other Income (Expense) 112 113 0.3% 0.1% 0.0% (91.1%) (2,2683.5%) --------------------------------------------------- (3.3%) (1.6%) (4.0%) ---------------------------------------------------------------------------- Income Before Taxes 4,210 7,906 10,887 10,400 10.0% 8.6% 8.8% 5.2% 1.9% 0.0% 6.6% 0.1% Provision (Creditcredit) for Income Taxes 1,842 3,312 4,270 4,552 --------------------------------------------------- 4.4% 3.6% 3.5% 2.3% 1.0% 0.0% 2.7% 0.2% ---------------------------------------------------------------------------- Net Income $ 2,368 $ 4,594 $ 6,617 $ 5,848 5.6% 5.0% 5.4% 2.9% 1.0% 0.0% 3.9% (0.1%) ============================================================================ Basic Earnings Per Share $ 0.25 $ 0.41 $ 0.53 $ 0.40 Depreciation and Amortization 1,273 3,720 4,493 6,615 --------------------------------------------------- 3.0% 4.1% 3.6% 3.3% 4.5% 4.6% 3.4% 4.9% ---------------------------------------------------------------------------- EBITDA 5,371 11,513 15,389 19,283 12.7% 12.6% 12.5% 9.7% 9.9% 8.0% 11.7% 8.9% ============================================================================ ▇▇▇▇▇▇ ▇▇▇▇▇▇ 12.7Projected ---------------------------------------------- 1999 2000 2001 2002 2003 ---- ---- ---- ---- ---- Revenues 100.0% 12.6100.0% 12.5100.0% 9.7100.0% 100.0% Cost of Revenues 54.3% 53.4% 53.0% 52.5% 52.4% ---------------------------------------------- Gross Profit 45.7% 46.6% 47.0% 47.5% 47.6%