Frequencies for first 10,000 rows of comstat2 variable in namcs2008 dataset :

composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      4,860       48.60       48.60
  combination drug |        789        7.89       56.49
      undetermined |          5        0.05       56.54
                 . |      4,346       43.46      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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