Frequencies for first 10,000 rows of comstat1 variable in nhamcsed2003 dataset :

composition status |
          code for |
     medication #1 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      6,291       62.91       62.91
  combination drug |      1,236       12.36       75.27
      undetermined |        174        1.74       77.01
                 . |      2,299       22.99      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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