<ARTICLE> 5
<LEGEND>
This schedule contains summary financial information extracted from Form 10-K/A
for the year ended December 31, 1999, and is qualified in its entirety by
reference to such financial statements.



                             
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-START>                             JAN-01-1999
<PERIOD-END>                               DEC-31-1999
<CASH>                                      31,001,354
<SECURITIES>                                         0
<RECEIVABLES>                              128,917,491
<ALLOWANCES>                                 2,440,544
<INVENTORY>                                          0
<CURRENT-ASSETS>                           187,839,131
<PP&E>                                     238,189,810
<DEPRECIATION>                             103,433,932
<TOTAL-ASSETS>                             419,395,841
<CURRENT-LIABILITIES>                       94,764,085
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                       427,343
<OTHER-SE>                                 194,959,421
<TOTAL-LIABILITY-AND-EQUITY>               419,395,841
<SALES>                                    572,741,697
<TOTAL-REVENUES>                           572,741,697
<CGS>                                                0
<TOTAL-COSTS>                              369,849,565
<OTHER-EXPENSES>                           163,621,773
<LOSS-PROVISION>                               151,803
<INTEREST-EXPENSE>                           3,669,327
<INCOME-PRETAX>                             35,752,835
<INCOME-TAX>                                13,850,424
<INCOME-CONTINUING>                         21,902,411
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                21,902,411
<EPS-BASIC>                                       0.52
<EPS-DILUTED>                                     0.51