<ARTICLE> 5 <MULTIPLIER> 1,000 <PERIOD-TYPE> YEAR <FISCAL-YEAR-END> SEP-30-1998 <PERIOD-START> OCT-01-1997 <PERIOD-END> SEP-30-1998 <CASH> 24,476 <SECURITIES> 200,400 <RECEIVABLES> 121,303 <ALLOWANCES> 1,908 <INVENTORY> 25,401 <CURRENT-ASSETS> 184,345 <PP&E> 1,378,535 <DEPRECIATION> 686,164 <TOTAL-ASSETS> 1,090,430 <CURRENT-LIABILITIES> 125,484 <BONDS> 0 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 5,353 <OTHER-SE> 787,795 <TOTAL-LIABILITY-AND-EQUITY> 1,090,430 <SALES> 592,037 <TOTAL-REVENUES> 636,640 <CGS> 472,619 <TOTAL-COSTS> 472,619 <OTHER-EXPENSES> 10,859 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 942 <INCOME-PRETAX> 152,220 <INCOME-TAX> 56,677 <INCOME-CONTINUING> 101,154 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 101,154 <EPS-PRIMARY> 2.03 <EPS-DILUTED> 2.00