Frequencies for first 10,000 rows of comstat1 variable in nhamcsed2010 dataset :

Composition status |
   code for med #1 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      6,449       64.49       64.49
  combination drug |      1,345       13.45       77.94
      undetermined |         66        0.66       78.60
                 . |      2,140       21.40      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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