Frequencies for first 10,000 rows of comstat8 variable in namcs2009 dataset :

composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |        808        8.08        8.08
  combination drug |         80        0.80        8.88
      undetermined |         16        0.16        9.04
                 . |      9,096       90.96      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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