
<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM CONSOLIDATED
BALANCE SHEETS CONSOLIDATED STATEMENTS OF INCOME AND IS QUALIFIED IN ITS 
ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-START>                             JAN-01-1998
<PERIOD-END>                               SEP-30-1998
<CASH>                                          25,646
<SECURITIES>                                         0
<RECEIVABLES>                                   39,862
<ALLOWANCES>                                   (1,200)
<INVENTORY>                                          0
<CURRENT-ASSETS>                               102,408
<PP&E>                                         114,982
<DEPRECIATION>                                (54,286)
<TOTAL-ASSETS>                                 203,286
<CURRENT-LIABILITIES>                          110,399
<BONDS>                                         31,000
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           178
<OTHER-SE>                                      51,807
<TOTAL-LIABILITY-AND-EQUITY>                    51,985
<SALES>                                              0
<TOTAL-REVENUES>                               257,862
<CGS>                                                0
<TOTAL-COSTS>                                  200,925
<OTHER-EXPENSES>                                10,271
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               1,951
<INCOME-PRETAX>                                 46,713
<INCOME-TAX>                                    17,980
<INCOME-CONTINUING>                             28,733
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    28,733
<EPS-PRIMARY>                                     1.50
<EPS-DILUTED>                                     1.61
        

</TABLE>
