Frequencies for first 10,000 rows of comstat5 variable in namcs2012 dataset :

Composition status |
          code for |
      medication 5 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |      1,674       16.74       16.74
  Combination drug |        150        1.50       18.24
      Undetermined |         56        0.56       18.80
                 . |      8,120       81.20      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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