Frequencies for first 10,000 rows of comstat3 variable in namcs2012 dataset :

Composition status |
          code for |
      medication 3 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |      3,099       30.99       30.99
  Combination drug |        274        2.74       33.73
      Undetermined |         94        0.94       34.67
                 . |      6,533       65.33      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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