Frequencies for first 10,000 rows of comstat2 variable in namcs2014 dataset :

Composition status |
          code for |
     medication #2 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |      4,946       49.46       49.46
  Combination drug |        626        6.26       55.72
      Undetermined |        153        1.53       57.25
                 . |      4,275       42.75      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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