Frequencies for first 10,000 rows of comstat3 variable in nhamcsed2003 dataset :

composition status |
          code for |
     medication #3 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      2,276       22.76       22.76
  combination drug |        428        4.28       27.04
      undetermined |         88        0.88       27.92
                 . |      7,208       72.08      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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