Frequencies for first 10,000 rows of comstat6 variable in nhamcsed2003 dataset :

composition status |
          code for |
     medication #6 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |        469        4.69        4.69
  combination drug |         48        0.48        5.17
      undetermined |         26        0.26        5.43
                 . |      9,457       94.57      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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