Frequencies for first 10,000 rows of comstat6 variable in namcs2010 dataset :

composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      1,390       13.90       13.90
  combination drug |        127        1.27       15.17
      undetermined |         14        0.14       15.31
                 . |      8,469       84.69      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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