Frequencies for first 10,000 rows of comstat1 variable in namcs2002 dataset :

Composition status |
          code for |
     medication #1 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |      4,901       49.01       49.01
  Combination drug |        915        9.15       58.16
      Undetermined |        281        2.81       60.97
                 . |      3,903       39.03      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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