Frequencies for first 10,000 rows of comstat7 variable in nhamcsed2007 dataset :

          for rx7, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |        252        2.52        2.52
  combination drug |         20        0.20        2.72
                 . |      9,728       97.28      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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