Frequencies for first 10,000 rows of comstat28 variable in namcs2014 dataset :

Composition status |
          code for |
    medication #28 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |          9        0.09        0.09
  Combination drug |          2        0.02        0.11
      Undetermined |          1        0.01        0.12
                 . |      9,988       99.88      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 27 Mar 2017