Item 6. Selected Financial Data Year ended December 31, 2014 2013 2012 2011 2010 (In thousands, except per share amounts) Statement of Operations Data: Revenues: Products ................................ $773,205 $731,617 $610,218 $511,650 $486,050 Services ................................ 157,752 140,755 122,813 89,692 80,201 Total revenues ....................... 930,957 872,372 733,031 601,342 566,251 Cost and expenses: Cost of sales: Products ................................ 428,125 436,359 384,513 303,995 272,619 Services ................................ 85,402 77,547 67,153 57,853 49,988 Total cost of sales .................... 513,527 513,906 451,666 361,848 322,607 Selling, general and administrative ............... 92,762 94,806 82,218 70,510 61,069 Engineering and product development ............ 45,920 40,115 37,455 34,626 29,202 Special items ................................ — — — 4,719 14,660 Operating income ............................ 278,748 223,545 161,692 129,639 138,713 Interest income .............................. 667 587 462 418 321 Interest expense .............................. (35) (35) (32) (53) (131) Income before income taxes .................... 279,380 224,097 162,122 130,004 138,903 Income tax provision .......................... 70,668 54,270 42,913 34,737 36,677 Net income ................................. $208,712 $169,827 $119,209 $ 95,267 $102,226 Earnings per common share: Basic .................................. $ 5.22 $ 4.18 $ 2.96 $ 2.38 $ 2.57 Diluted ................................. $ 5.19 $ 4.16 $ 2.94 $ 2.36 $ 2.55 Weighted average common shares outstanding: Basic .................................. 39,964 40,648 40,332 40,071 39,828 Diluted ................................. 40,190 40,865 40,523 40,322 40,060 Statement of Cash Flows Data: Net cash provided by (used in) operating activities . . 149,313 162,229 (8,159) $101,854 $107,160 Net cash used in investing activities .............. (41,571) (41,873) (48,999) (54,187) (72,950) Net cash provided by (used in) financing activities . . (186,827) 3,367 12,257 5,098 14,634 Other Data: Depreciation and amortization .................. $ 31,155 $ 29,340 $ 26,224 $ 23,013 $ 20,875 Capital expenditures .......................... 42,549 42,633 50,773 56,213 74,815 December 31, 2014 2013 2012 2011 2010 (In thousands) Balance Sheet Data: Working capital ............................. $ 928,498 $ 931,563 $ 769,299 $ 648,302 $576,920 Total assets ................................. 1,449,251 1,396,805 1,249,708 1,094,715 948,551 Total debt .................................. — — — 57 326 Total stockholders’ equity ..................... 1,245,192 1,242,018 1,066,432 925,244 828,014 The information set forth below should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and the Consolidated Financial Statements and Notes thereto included elsewhere in this report on Form 10-K. 28