Frequencies for first 10,000 rows of comstat4 variable in namcs2002 dataset :

Composition status |
          code for |
     medication #4 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |      1,048       10.48       10.48
  Combination drug |        121        1.21       11.69
      Undetermined |         42        0.42       12.11
                 . |      8,789       87.89      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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