<TABLE> <S> <C>

<ARTICLE> 5
       
<S>                             <C>               <C>               <C>               <C>        
<PERIOD-TYPE>                   3-MOS             3-MOS             3-MOS             3-MOS     
<FISCAL-YEAR-END>               DEC-31-1996       DEC-31-1996       DEC-31-1996       DEC-31-1996
<PERIOD-START>                  JAN-01-1996       APR-01-1996       JUL-01-1996       OCT-01-1996
<PERIOD-END>                    MAR-31-1996       JUN-30-1996       SEP-30-1996       DEC-31-1996
<CASH>                            102,338           105,452           104,794           118,528  
<SECURITIES>                      106,075           114,092           112,657           118,703  
<RECEIVABLES>                      54,519            54,949            63,383            76,193  
<ALLOWANCES>                            0                 0                 0                 0  
<INVENTORY>                             0                 0                 0                 0  
<CURRENT-ASSETS>                  263,697           297,916           312,602           346,088  
<PP&E>                             48,198            53,527            56,804            63,180  
<DEPRECIATION>                   (26,975)          (31,334)          (33,615)          (37,299)  
<TOTAL-ASSETS>                    335,426           359,384           395,854           446,296  
<CURRENT-LIABILITIES>              77,261            81,818            83,181            95,519  
<BONDS>                                 0                 0                 0                 0  
<PREFERRED-MANDATORY>                 660               669               690               666  
<PREFERRED>                             0                 0                 0                 0  
<COMMON>                                0                 0                 0                 0  
<OTHER-SE>                        251,518           271,424           305,669           328,257  
<TOTAL-LIABILITY-AND-EQUITY>      335,426           359,384           395,854           446,296  
<SALES>                            87,631            92,447           102,835           124,662  
<TOTAL-REVENUES>                   87,631            92,447           102,835           124,662  
<CGS>                              14,633            15,423            16,810            20,949  
<TOTAL-COSTS>                      53,043            51,178            52,888            61,725  
<OTHER-EXPENSES>                        0                 0                 0                 0  
<LOSS-PROVISION>                        0                 0                 0                 0  
<INTEREST-EXPENSE>                      0                 0                 0                 0  
<INCOME-PRETAX>                    22,313            28,182            35,664            44,811  
<INCOME-TAX>                       10,880            10,097            12,940            16,168  
<INCOME-CONTINUING>                11,433            18,085            22,724            28,643  
<DISCONTINUED>                          0                 0                 0                 0  
<EXTRAORDINARY>                         0                 0                 0                 0  
<CHANGES>                               0                 0                 0                 0  
<NET-INCOME>                       11,433            18,085            22,724            28,643  
<EPS-PRIMARY>                        0.18              0.28              0.34              0.43  
<EPS-DILUTED>                        0.16              0.25              0.31              0.39  
        

</TABLE>