Calculate the percentages by subgroups with proc tabulate

I have the following table:

Suppose to look at Drug3 dosage 0.75 and 1.5.
Is there a way with proc tabulate or another proc to compute the percentage on 21520 + 34732? In other words, the percentage for 0.75 should be 21520/(21520 + 34732)=38% and for 1.5 should be 34732/(21520 + 34732)=61%

Thank you in advance

Try multi-label formats. Here is sashelp.class example:

proc format library=work;
  value agef (multilabel notsorted)
  11='11'
  12='12'
  13='13'
  11-13='11-13'
  14='14'
  15='15'
  16='16'
  14-16='14-16';
  value $sexf
  'F'='Female'
  'M'='Male';
  picture myPercent
  0-high = '0000009.000%';
run;
proc tabulate data=sashelp.class format=8.1;
  class age / mlf preloadfmt order=data;
  class sex;
  var height;
  table age, sex*height*(mean N colPctn*f=myPercent10.2);
  format age agef. sex $sexf.;
  title 'PROC TABULATE';
run;

Output from the code

The code is from this article about it:
https://blogs.sas.com/content/sgf/2016/12/16/creating-and-using-multilabel-formats/ with examples for Proc Tabulate.

This technique will allow you to group 0.75 and 1.5 into an additional "virtual group" and get the result for it.