<ARTICLE> 5
<LEGEND>
This schedule contains summary financial information extracted from the
condensed consolidated balance sheets and the condensed consolidated statements
of earnings at the date and for the period indicated and is qualified in its
entirety by reference to such financial statements. All amounts shown are in
thousands of dollars, except per share data.


                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          MAR-31-2001
<PERIOD-START>                             APR-01-2000
<PERIOD-END>                               DEC-31-2000
<CASH>                                          85,880
<SECURITIES>                                         0
<RECEIVABLES>                                  169,919
<ALLOWANCES>                                     8,256
<INVENTORY>                                     26,652
<CURRENT-ASSETS>                               275,624
<PP&E>                                       1,598,272
<DEPRECIATION>                                 861,133
<TOTAL-ASSETS>                               1,490,456
<CURRENT-LIABILITIES>                           70,969
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                         6,056
<OTHER-SE>                                   1,146,269
<TOTAL-LIABILITY-AND-EQUITY>                 1,490,456
<SALES>                                        442,148
<TOTAL-REVENUES>                               442,148
<CGS>                                          398,257
<TOTAL-COSTS>                                  398,257
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                 650
<INCOME-PRETAX>                                 84,250
<INCOME-TAX>                                    27,466
<INCOME-CONTINUING>                             56,794
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    56,794
<EPS-BASIC>                                       1.02
<EPS-DILUTED>                                     1.01