Frequencies for first 10,000 rows of comstat6 variable in nhamcsed2011 dataset :

Composition status |
          code for |
     medication #6 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        477        4.77        4.77
  Combination drug |         59        0.59        5.36
      Undetermined |          5        0.05        5.41
                 . |      9,459       94.59      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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