Frequencies for first 10,000 rows of comstat9 variable in nhamcsed2014 dataset :

Composition status |
          code for |
     medication #9 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        237        2.37        2.37
  Combination drug |         23        0.23        2.60
      Undetermined |          4        0.04        2.64
                 . |      9,736       97.36      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 11 Apr 2017