Frequencies for first 10,000 rows of comstat9 variable in namcs2012 dataset :

Composition status |
          code for |
     medication #9 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        637        6.37        6.37
  Combination drug |         57        0.57        6.94
      Undetermined |         17        0.17        7.11
                 . |      9,289       92.89      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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