Frequencies for first 10,000 rows of comstat3 variable in namcs2014 dataset :

Composition status |
          code for |
     medication #3 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |      3,883       38.83       38.83
  Combination drug |        431        4.31       43.14
      Undetermined |        108        1.08       44.22
                 . |      5,578       55.78      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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