<TABLE> <S> <C>
<PAGE>
<ARTICLE> 5
<S> <C> <C> <C>
<PERIOD-TYPE> 12-MOS 12-MOS 12-MOS
<FISCAL-YEAR-END> DEC-31-1999 DEC-31-1998 DEC-31-1997
<PERIOD-END> DEC-31-1999 DEC-31-1998 DEC-31-1997
<CASH> 16,227 9,466 7,477
<SECURITIES> 41,621 37,107 69,633
<RECEIVABLES> 95,902 77,512 45,991
<ALLOWANCES> 3,923 2,900 2,327
<INVENTORY> 0 0 0
<CURRENT-ASSETS> 10,250 6,666 4,192
<PP&E> 177,629 117,985 75,550
<DEPRECIATION> 65,985 38,998 21,812
<TOTAL-ASSETS> 311,484 238,957 194,947
<CURRENT-LIABILITIES> 74,507 62,272 43,763
<BONDS> 0 0 0
0 0 0
0 0 0
<COMMON> 650 639 625
<OTHER-SE> 210,148 168,425 138,776
<TOTAL-LIABILITY-AND-EQUITY> 311,484 238,957 194,947
<SALES> 549,076 384,771 284,683
<TOTAL-REVENUES> 549,076 384,771 284,683
<CGS> 372,182 253,427 182,509
<TOTAL-COSTS> 503,119 351,257 251,256
<OTHER-EXPENSES> (9,344) (1,583) (3,465)
<LOSS-PROVISION> 0 0 0
<INTEREST-EXPENSE> 2,509 1,446 1,166
<INCOME-PRETAX> 52,792 33,651 35,726
<INCOME-TAX> 20,847 13,344 14,206
<INCOME-CONTINUING> 31,945 20,307 21,520
<DISCONTINUED> 0 0 0
<EXTRAORDINARY> 0 0 0
<CHANGES> 0 0 0
<NET-INCOME> 31,945 20,307 21,520
<EPS-BASIC> .50 .32 .35
<EPS-DILUTED> .48 .31 .33
</TABLE>