data a;
   input x1 $;
   cards;
   a
b
  c
  c
   a
   ;
run;



ods trace on;
proc freq data=a;
tables x1;
output out=x ;
run;
ods trace off;

ods output "One-Way Frequencies"=out1;
proc freq data=a;
tables x1;
run;
ods output close;

The out1 is the one you need.

proc freq data=a;
tables x1/outpct out=x ;
run;