SAS RANDOM SAMPLING, WITH GROUP SIZE

I have a data set with accounts and its attribute (there are 9 main attributes). Each attribute group contains a different amount of account, where 2 groups hold a massively higher amount of accounts. Therefore, when I use PROC SURVEYSELECT, to randomly select 5 accounts per STRATA, and the METHOD=SRS, I get more results from attributes which contain more accounts. How can I correct that? how can I make SAS consider the group's volume when sampling?

The above mentioned code:

PROC SURVEYSELECT DATA=FINAL_RANDOM OUT=FINAL_RANDOM_1 NOPRINT 
     METHOD=srs
     SAMPSIZE = 5 
     SELECTALL;
     STRATA Account_Branch_Id ; 
RUN;