<ARTICLE> 5

                                                                       
<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
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                          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