data a;
input id x;
datalines;
1001 11
1001 12
1001 13
1002 21
1002 10
1002 23
1002 12
1002 11
1003 14
1003 16
;
run;
data a;
set a;
by id;
if first.id then count=0;
count+1;
run;
proc transpose data=a out=b prefix=y;
var x;
by id;
id count;
run;
proc print data=b;run;