Frequencies for first 10,000 rows of comstat3 variable in namcs2002 dataset :

Composition status |
          code for |
     medication #3 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |      1,736       17.36       17.36
  Combination drug |        211        2.11       19.47
      Undetermined |         68        0.68       20.15
                 . |      7,985       79.85      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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