Frequencies for first 10,000 rows of comstat5 variable in namcs2008 dataset :

composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      1,876       18.76       18.76
  combination drug |        197        1.97       20.73
      undetermined |          2        0.02       20.75
                 . |      7,925       79.25      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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