<ARTICLE> 5
       
                                                                                                      
<PERIOD-TYPE>              3-MOS                6-MOS                   9-MOS                  12-MOS              YEAR
<FISCAL-YEAR-END>              DEC-31-1996         DEC-31-1996             DEC-31-1996             DEC-31-1996        DEC-31-1996
<PERIOD-START>                 JAN-01-1996         JAN-01-1996             JAN-01-1996             JAN-01-1996        JAN-01-1996
<PERIOD-END>                   MAR-31-1996         JUN-30-1996             SEP-30-1996             DEC-31-1996        DEC-31-1996
<CASH>                               1,229               4,027                   1,711                   1,353              1,353
<SECURITIES>                             0                   0                       0                       0                  0
<RECEIVABLES>                       43,699              46,000                  48,175                  45,682             45,682
<ALLOWANCES>                        (5,260)             (5,309)                 (5,633)                 (5,699)            (5,699)
<INVENTORY>                              0                   0                       0                       0                  0
<CURRENT-ASSETS>                    51,109              56,002                  56,050                  56,264             56,264
<PP&E>                             159,429             172,148                 180,497                 180,009            180,009
<DEPRECIATION>                     (64,043)            (67,856)                (67,915)                (70,924)           (70,924)
<TOTAL-ASSETS>                     151,841             165,299                 173,552                 170,726            170,726
<CURRENT-LIABILITIES>               38,684              35,105                  35,206                  35,865             35,865
<BONDS>                                  0                   0                       0                       0                  0
<PREFERRED-MANDATORY>                    0                   0                       0                       0                  0
<PREFERRED>                              0                   0                       0                       0                  0
<COMMON>                               835                 835                     835                     835                835
<OTHER-SE>                          68,606              70,249                  72,429                  74,093             74,093
<TOTAL-LIABILITY-AND-EQUITY>       151,841             165,299                 173,552                 170,726            170,726
<SALES>                             68,262             143,124                 220,403                 293,006            293,006
<TOTAL-REVENUES>                    68,262             143,124                 220,403                 293,006            293,006
<CGS>                                    0                   0                       0                       0                  0
<TOTAL-COSTS>                       66,566             138,035                 210,805                 280,056            280,056
<OTHER-EXPENSES>                        90                 184                     327                     137                137
<LOSS-PROVISION>                         0                   0                       0                       0                  0
<INTEREST-EXPENSE>                     546               1,195                   2,046                   2,903              2,903
<INCOME-PRETAX>                      1,060               3,710                   7,225                   9,910              9,910
<INCOME-TAX>                           403               1,410                   2,745                   3,766              3,766
<INCOME-CONTINUING>                    657               2,300                   4,480                   6,144              6,144
<DISCONTINUED>                           0                   0                       0                       0                  0
<EXTRAORDINARY>                          0                   0                       0                       0                  0
<CHANGES>                                0                   0                       0                       0                  0
<NET-INCOME>                           657               2,300                   4,480                   6,144              6,144
<EPS-PRIMARY>                         0.08                0.28                    0.54                    0.74               0.74
<EPS-DILUTED>                         0.08                0.28                    0.54                    0.74               0.74