Frequencies for first 10,000 rows of comstat5 variable in nhamcsed2012 dataset :

Composition status |
code medication #5 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        908        9.08        9.08
  Combination drug |        137        1.37       10.45
      Undetermined |          5        0.05       10.50
                 . |      8,950       89.50      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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