proc summary data=my_data;
CLASS 类别;
VAR 人数;
output out= data_want sum=;
run;
年份 just change CLASS to 年份;
proc summary data=my_data nway;
CLASS 类别 年份;
VAR 人数;
output out= data_want sum=;
run;
if you want to use BY instead of CLASS, table need to be sorted first.