Frequencies for first 10,000 rows of comstat6 variable in namcs2009 dataset :

composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      1,491       14.91       14.91
  combination drug |        163        1.63       16.54
      undetermined |         29        0.29       16.83
                 . |      8,317       83.17      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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