<ARTICLE> 5
       
                                                  
<PERIOD-TYPE>                   3-MOS                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1996             DEC-31-1995
<PERIOD-END>                               MAR-31-1996             DEC-31-1995
<CASH>                                     108,156,879               16,802,144
<SECURITIES>                                87,046,579               96,923,514
<RECEIVABLES>                               52,050,043               44,389,879
<ALLOWANCES>                                         0                        0
<INVENTORY>                                 24,831,487               20,591,717
<CURRENT-ASSETS>                           562,440,465              497,184,935
<PP&E>                                   1,121,883,213            1,105,455,333
<DEPRECIATION>                             305,863,139              300,480,854
<TOTAL-ASSETS>                           1,650,868,804            1,530,995,011
<CURRENT-LIABILITIES>                       55,732,424               44,469,522
<BONDS>                                              0                        0
<COMMON>                                     8,713,900                8,713,900
<PREFERRED-MANDATORY>                                0                        0
<PREFERRED>                                          0                        0
<OTHER-SE>                               1,079,333,927            1,007,352,932
<TOTAL-LIABILITY-AND-EQUITY>             1,650,868,804            1,530,995,011
<SALES>                                    125,518,878              148,072,825
<TOTAL-REVENUES>                           170,962,134              334,924,340
<CGS>                                       34,275,586              116,014,000
<TOTAL-COSTS>                               77,563,643              287,606,464
<OTHER-EXPENSES>                                     0                        0
<LOSS-PROVISION>                                     0                        0
<INTEREST-EXPENSE>                              67,399                2,234,854
<INCOME-PRETAX>                            102,304,844               66,087,305
<INCOME-TAX>                                39,197,000               24,535,000
<INCOME-CONTINUING>                         59,678,680               29,358,040
<DISCONTINUED>                              13,864,530               70,576,624
<EXTRAORDINARY>                                      0                        0
<CHANGES>                                            0                        0
<NET-INCOME>                                68,568,109               73,818,564
<EPS-PRIMARY>                                     2.25                     2.42
<EPS-DILUTED>                                     2.25                     2.42