EXHIBIT
  12.1STATEMENT OF COMPUTATION OF RATIO
      OF EARNINGSTO FIXED
      CHARGES(In
    thousands)2004
                                                                                
                                                                                
                                                                                2005
                                                                                
                                                                                
                                                                                2006
                                                                                
                                                                                
                                                                                2007
                                                                                
                                                                                
                                                                                2008Earnings:Income before income
      taxes
                                                                                
                                                                                $
                                                                                115,609
                                                                                
                                                                                
                                                                                
                                                                                132,588
                                                                                
                                                                                
                                                                                
                                                                                125,752
                                                                                
                                                                                
                                                                                
                                                                                158,998
                                                                                
                                                                                
                                                                                
                                                                                163,956Plus:  fixed charges per
      below
                                                                                
                                                                                
                                                                                23,999
                                                                                
                                                                                
                                                                                
                                                                                26,547
                                                                                
                                                                                
                                                                                
                                                                                32,399
                                                                                
                                                                                
                                                                                
                                                                                36,657
                                                                                
                                                                                
                                                                                
                                                                                37,887Less: capitalized interest per
      below
                                                                                
                                                                                
                                                                                167
                                                                                
                                                                                
                                                                                
                                                                                432
                                                                                
                                                                                
                                                                                
                                                                                654
                                                                                
                                                                                
                                                                                
                                                                                206
                                                                                
                                                                                
                                                                                
                                                                                29Plus:  current period
      amortization of interestcapitalized in prior
      periods
                                                                                
                                                                                
                                                                                13
                                                                                
                                                                                
                                                                                
                                                                                21
                                                                                
                                                                                
                                                                                
                                                                                30
                                                                                
                                                                                
                                                                                
                                                                                39
                                                                                
                                                                                
                                                                                
                                                                                39Total
    earnings
                                                                                
                                                                                $
                                                                                139,454
                                                                                
                                                                                
                                                                                $
                                                                                158,724
                                                                                
                                                                                
                                                                                $
                                                                                157,527
                                                                                
                                                                                
                                                                                $
                                                                                195,488
                                                                                
                                                                                
                                                                                $
                                                                                201,853Fixed
    chargesInterest
      expense
                                                                                
                                                                                $
                                                                                21,724
                                                                                
                                                                                
                                                                                $
                                                                                23,489
                                                                                
                                                                                
                                                                                $
                                                                                28,970
                                                                                
                                                                                
                                                                                $
                                                                                33,430
                                                                                
                                                                                
                                                                                $
                                                                                35,527Capitalized
      interest
                                                                                
                                                                                
                                                                                167
                                                                                
                                                                                
                                                                                
                                                                                432
                                                                                
                                                                                
                                                                                
                                                                                654
                                                                                
                                                                                
                                                                                
                                                                                206
                                                                                
                                                                                
                                                                                
                                                                                29Interest portion of rent
      expense
                                                                                
                                                                                
                                                                                2,108
                                                                                
                                                                                
                                                                                
                                                                                2,626
                                                                                
                                                                                
                                                                                
                                                                                2,775
                                                                                
                                                                                
                                                                                
                                                                                3,021
                                                                                
                                                                                
                                                                                
                                                                                2,331Total fixed
      charges
                                                                                
                                                                                $
                                                                                23,999
                                                                                
                                                                                
                                                                                $
                                                                                26,547
                                                                                
                                                                                
                                                                                $
                                                                                32,399
                                                                                
                                                                                
                                                                                $
                                                                                36,657
                                                                                
                                                                                
                                                                                $
                                                                                37,887Ratio of earnings to fixed
      charges
                                                                                
                                                                                
                                                                                5.8
                                                                                
                                                                                
                                                                                
                                                                                6.0
                                                                                
                                                                                
                                                                                
                                                                                4.9
                                                                                
                                                                                
                                                                                
                                                                                5.3
                                                                                
                                                                                
                                                                                
                                                                                5.3