<TABLE> <S> <C>

<PAGE>
 
<ARTICLE> 5
<MULTIPLIER> 1,000
       
<S>                                    <C>                     <C>                     <C>
<PERIOD-TYPE>                          9-MOS                   6-MOS                   3-MOS
<FISCAL-YEAR-END>                          SEP-30-1997             SEP-30-1997             SEP-30-1997
<PERIOD-END>                               JUN-30-1997             MAR-31-1997             DEC-31-1996
<CASH>                                          13,288                  10,351                  21,322
<SECURITIES>                                         0                       0                       0
<RECEIVABLES>                                  266,602                 261,461                 261,444
<ALLOWANCES>                                    36,731                  33,894                  29,600
<INVENTORY>                                     20,395                  16,743                  16,005
<CURRENT-ASSETS>                               296,853                 289,575                 306,103
<PP&E>                                         504,607                 495,817                 488,891
<DEPRECIATION>                                 205,187                 198,804                 193,491
<TOTAL-ASSETS>                                 881,557                 866,260                 861,382
<CURRENT-LIABILITIES>                          142,268                 142,469                 172,723
<BONDS>                                        309,467                 311,233                 295,270
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                          0                       0                       0
<COMMON>                                           608                     608                     608
<OTHER-SE>                                     366,210                 352,201                 339,309
<TOTAL-LIABILITY-AND-EQUITY>                   881,557                 866,260                 861,382
<SALES>                                        853,953                 565,520                 280,202
<TOTAL-REVENUES>                               853,953                 565,520                 280,202
<CGS>                                                0                       0                       0
<TOTAL-COSTS>                                  777,971                 517,994                 258,520
<OTHER-EXPENSES>                                     0                       0                       0
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                              12,924                   8,436                   4,054
<INCOME-PRETAX>                                 63,058                  39,090                  17,628
<INCOME-TAX>                                    26,445                  16,369                   7,240
<INCOME-CONTINUING>                             36,208                  22,539                  10,325
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                         0                       0                       0
<EPS-PRIMARY>                                     0.62                    0.38                    0.18<F1>
<EPS-DILUTED>                                     0.61                    0.38                    0.18
<FN>
<F1>EPS-Primary reflects EPS-Basic
</FN>
        


</TABLE>