Frequencies for first 10,000 rows of comstat2 variable in namcs2007 dataset :

composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      4,430       44.30       44.30
  combination drug |        718        7.18       51.48
                 . |      4,852       48.52      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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