Frequencies for first 10,000 rows of comstat1 variable in namcs2006 dataset :

          for rx1, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      6,329       63.29       63.29
  combination drug |      1,235       12.35       75.64
                 . |      2,436       24.36      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016