Frequencies for first 10,000 rows of comstat8 variable in nhamcsed2012 dataset :

Composition status |
          code for |
     medication #8 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        245        2.45        2.45
  Combination drug |         30        0.30        2.75
      Undetermined |          1        0.01        2.76
                 . |      9,724       97.24      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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