Frequencies for first 10,000 rows of comstat8 variable in nhamcsed2011 dataset :

Composition status |
          code for |
     medication #8 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        184        1.84        1.84
  Combination drug |         22        0.22        2.06
      Undetermined |          1        0.01        2.07
                 . |      9,793       97.93      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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