Frequencies for first 10,000 rows of comstat6 variable in nhamcsopd2004 dataset :

composition status |
          code for |
     medication #6 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |        935        9.35        9.35
  combination drug |         91        0.91       10.26
      undetermined |         18        0.18       10.44
                 . |      8,956       89.56      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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