Hi everyone, wondering if anyone can help as I seem stuck.

I have a dataset with 105 hospitals and each hospital has a varying number of patients- total patient(24000). I want to select 6 hospital but make sure it represents approximately 20% of patients (total -4910). But not sure how. So far i have tried

bsample 6, cluster ()

But this just randomly gives any 6 hospital sometimes is more than 20% and sometimes less.

Is there anything else I can try?

Many thanks