Frequencies for first 10,000 rows of comstat4 variable in nhamcsed2004 dataset :

composition status |
          code for |
     medication #4 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      1,495       14.95       14.95
  combination drug |        244        2.44       17.39
      undetermined |         66        0.66       18.05
                 . |      8,195       81.95      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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