Frequencies for first 10,000 rows of comstat1 variable in namcs2012 dataset :

Composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |      5,811       58.11       58.11
  Combination drug |        800        8.00       66.11
      Undetermined |        228        2.28       68.39
                 . |      3,161       31.61      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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