Frequencies for first 10,000 rows of comstat8 variable in namcs2010 dataset :

composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |        757        7.57        7.57
  combination drug |         76        0.76        8.33
      undetermined |          8        0.08        8.41
                 . |      9,159       91.59      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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