Frequencies for first 10,000 rows of comstat7 variable in nhamcsed2012 dataset :

Composition status |
          code for |
     medication #7 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        345        3.45        3.45
  Combination drug |         40        0.40        3.85
      Undetermined |          4        0.04        3.89
                 . |      9,611       96.11      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 7 Nov 2016