Frequencies for first 10,000 rows of comstat2 variable in nhamcsed2003 dataset :

composition status |
          code for |
     medication #2 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      4,088       40.88       40.88
  combination drug |        771        7.71       48.59
      undetermined |        129        1.29       49.88
                 . |      5,012       50.12      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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