Frequencies for first 10,000 rows of comstat2 variable in namcs2002 dataset :

Composition status |
          code for |
     medication #2 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |      2,969       29.69       29.69
  Combination drug |        434        4.34       34.03
      Undetermined |        122        1.22       35.25
                 . |      6,475       64.75      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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