Frequencies for first 10,000 rows of comstat3 variable in namcs2008 dataset :

composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      3,464       34.64       34.64
  combination drug |        514        5.14       39.78
      undetermined |          2        0.02       39.80
                 . |      6,020       60.20      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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