<TABLE> <S> <C>

<ARTICLE> 5
<LEGEND>
THIS SCEDULE CONTAINS SUMMARY INFORMATION EXTRACTED FROM CONDENSED CONSOLIDATED
BALANCE SHEETS AND STATEMENTS OF OPERATIONS AS OF MARCH 31, 1996, JUNE 30, 1996
AND SEPTEMBER 30, 1996, AND FOR THE THREE, SIX AND NINE MONTH PERIODS,
RESPECTIVELY THEN ENDED, AND AS OF DECEMBER 31, 1996, AND FOR THE TWELVE MONTH
PERIOD THEN ENDED.  THIS SHEDULE IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO
SUCH FINANCIAL STATEMENTS.
</LEGEND>
<RESTATED>
<MULTIPLIER> 1,000

<S>                             <C>                     <C>                     <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   6-MOS                   9-MOS                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1996             DEC-31-1996             DEC-31-1996             DEC-31-1996
<PERIOD-START>                             JAN-01-1998             JAN-01-1996             JAN-01-1996             JAN-01-1996
<PERIOD-END>                               MAR-31-1996             JUN-30-1996             SEP-30-1996             DEC-31-1996
<CASH>                                           17570                   25850                   88704                  108321
<SECURITIES>                                         0                       0                       0                       0
<RECEIVABLES>                                    75198                   74784                   57237                   55096
<ALLOWANCES>                                      2710                    2637                    2583                    2840
<INVENTORY>                                      53313                   48453                   41713                   41326
<CURRENT-ASSETS>                                169568                  163415                  204662                  217952
<PP&E>                                         1167670                 1131340                 1136605                 1143036
<DEPRECIATION>                                  317162                  298366                  313179                  324166
<TOTAL-ASSETS>                                 1037650                 1010419                 1041174                 1050625
<CURRENT-LIABILITIES>                           134478                  116759                  137048                  133022
<BONDS>                                         344770                  344770                  344770                  344770
<PREFERRED-MANDATORY>                                0                       0                       0                       0
<PREFERRED>                                          0                       0                       0                       0
<COMMON>                                           283                     284                     284                     284
<OTHER-SE>                                       89921                  101212                  116086                  132322
<TOTAL-LIABILITY-AND-EQUITY>                   1037650                 1010419                 1041174                 1050625
<SALES>                                         172922                  347043                  533705                  698523
<TOTAL-REVENUES>                                180983                  363719                  556941                  731624
<CGS>                                           137839                  294559                  462487                  597100
<TOTAL-COSTS>                                   141972                  304956                  460414                  619614
<OTHER-EXPENSES>                                 21049                   19639                   31438                   22495
<LOSS-PROVISION>                                     0                       0                       0                       0
<INTEREST-EXPENSE>                                5777                   11652                   17186                   21042
<INCOME-PRETAX>                                  12185                   27472                   47943                   69264
<INCOME-TAX>                                      2072                    4685                    8165                   11300
<INCOME-CONTINUING>                              10113                   22787                   39778                   57964
<DISCONTINUED>                                       0                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0                       0
<CHANGES>                                            0                       0                       0                       0
<NET-INCOME>                                     10113                   22787                   39778                   57964
<EPS-PRIMARY>                                      .36                     .80                    1.40                    2.04
<EPS-DILUTED>                                      .36                     .80                    1.40                    2.04


</TABLE>