Frequencies for first 10,000 rows of comstat10 variable in nhamcsed2014 dataset :

Composition status |
          code for |
    medication #10 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        169        1.69        1.69
  Combination drug |         16        0.16        1.85
      Undetermined |          4        0.04        1.89
                 . |      9,811       98.11      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 11 Apr 2017