Frequencies for first 10,000 rows of comstat7 variable in namcs2009 dataset :

composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      1,122       11.22       11.22
  combination drug |        112        1.12       12.34
      undetermined |         21        0.21       12.55
                 . |      8,745       87.45      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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