Frequencies for first 10,000 rows of comstat6 variable in nhamcsed2012 dataset :

Composition status |
          code for |
     medication #6 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        553        5.53        5.53
  Combination drug |         67        0.67        6.20
      Undetermined |         10        0.10        6.30
                 . |      9,370       93.70      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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