Frequencies for first 10,000 rows of comstat7 variable in nhamcsopd2004 dataset :

composition status |
          code for |
     medication #7 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |        667        6.67        6.67
  combination drug |         70        0.70        7.37
      undetermined |         27        0.27        7.64
                 . |      9,236       92.36      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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