Frequencies for first 10,000 rows of comstat6 variable in nhamcsed2013 dataset :

Composition status |
          code for |
     medication #6 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        630        6.30        6.30
  Combination drug |        100        1.00        7.30
      Undetermined |          8        0.08        7.38
                 . |      9,262       92.62      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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