Frequencies for first 10,000 rows of comstat5 variable in nhamcsed2011 dataset :

Composition status |
code medication #5 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        806        8.06        8.06
  Combination drug |        107        1.07        9.13
      Undetermined |          8        0.08        9.21
                 . |      9,079       90.79      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016