Frequencies for first 10,000 rows of comstat6 variable in namcs2008 dataset :

composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      1,345       13.45       13.45
  combination drug |        154        1.54       14.99
      undetermined |          3        0.03       15.02
                 . |      8,498       84.98      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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