Frequencies for first 10,000 rows of comstat9 variable in nhamcsed2013 dataset :

Composition status |
          code for |
     medication #9 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        158        1.58        1.58
  Combination drug |         17        0.17        1.75
                 . |      9,825       98.25      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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