How to display the percentage symbol (%) next to the numbers on the y-axis of a P-chart (SPC chart)?

[bhr-q]

Hello, I can get the number based on the percentage displayed on the y-axis using the following code with (YSCALE=PERCENT).

How can I fix it to display the "%" symbol next to each number on the y-axis?

proc shewhart data=tmp2;
pchart yes_answer2*month /     subgroupn = n_per_group2 ODSTITLE="P-chart of Pts Counseling"
                                      outtable  = tmp2table  
                                      nohlabel nolegend  YSCALE=PERCENT ;    
LABEL yes_answer ="Prop of Pts counseled";
run;proc print noobs;run;

Thanks