<ARTICLE>                          5
<MULTIPLIER>                       1,000

                                
<FISCAL-YEAR-END>                  MAY-31-2001
<PERIOD-START>                     JUN-1-2000
<PERIOD-END>                       NOV-30-2000
<PERIOD-TYPE>                      6-MOS
<CASH>                                           3,445
<SECURITIES>                                        0
<RECEIVABLES>                                   35,714
<ALLOWANCES>                                     3,458
<INVENTORY>                                         0
<CURRENT-ASSETS>                                    0
<PP&E>                                         449,355
<DEPRECIATION>                                 249,828
<TOTAL-ASSETS>                                 298,284
<CURRENT-LIABILITIES>                               0
<BONDS>                                             0
<PREFERRED-MANDATORY>                               0
<PREFERRED>                                         0
<COMMON>                                        11,296
<OTHER-SE>                                          0
<TOTAL-LIABILITY-AND-EQUITY>                   298,284
<SALES>                                         19,482
<TOTAL-REVENUES>                               111,850
<CGS>                                           13,188
<TOTAL-COSTS>                                   82,883
<OTHER-EXPENSES>                                    0
<LOSS-PROVISION>                                    0
<INTEREST-EXPENSE>                                 608
<INCOME-PRETAX>                                 28,359
<INCOME-TAX>                                    10,777
<INCOME-CONTINUING>                             17,582
<DISCONTINUED>                                      0
<EXTRAORDINARY>                                     0
<CHANGES>                                           0
<NET-INCOME>                                    17,582
<EPS-BASIC>                                     0.72
<EPS-DILUTED>                                     0.71