Frequencies for first 10,000 rows of comstat9 variable in nhamcsed2012 dataset :

Composition status |
          code for |
     medication #9 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        157        1.57        1.57
  Combination drug |         14        0.14        1.71
      Undetermined |          4        0.04        1.75
                 . |      9,825       98.25      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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