Frequencies for first 10,000 rows of comstat5 variable in nhamcsopd2004 dataset :

composition status |
          code for |
     medication #5 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      1,220       12.20       12.20
  combination drug |        119        1.19       13.39
      undetermined |         30        0.30       13.69
                 . |      8,631       86.31      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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