i want a code for below data

[chittamsri1_gmail_com]

in o/p we have 3 variables stockname ,year,return

stockname  year return

tcs        2000 10%

tcs        2001 20%

tcs        2002 30%

tcs        2003 40%

tcs        2004 50%

hp         2000 20%

hp         2001 40%

hp         2002 50%

hp         2003 60%

hp         2004 70%

quest: by using above dataset we would create new data set with all the above variables and new varible 'growth' .finally i want a growth it should be automatically calculated by using below formula.give me a code for this. 

(formula) growth =(return(2001)-return(2000))

                  ----------------------------

                        return(2000)

[Ksharp]

A homework ?

data have;
input stockname $  year return : percent8.;
format return  percent8.;
cards;
tcs        2000 10%
tcs        2001 20%
tcs        2002 30%
tcs        2003 40%
tcs        2004 50%
hp         2000 20%
hp         2001 40%
hp         2002 50%
hp         2003 60%
hp         2004 70%
;
run;
data have;
set have;
g=dif(return)/lag(return);
if stockname ne lag(stockname) then call missing(g);
run;

Xia Keshan

[chittamsri1_gmail_com]

Thanks for your reply