Frequencies for first 10,000 rows of comstat5 variable in namcs2013 dataset :

Composition status |
          code for |
     medication #5 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |      2,189       21.89       21.89
  Combination drug |        217        2.17       24.06
      Undetermined |         64        0.64       24.70
                 . |      7,530       75.30      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 27 Mar 2017