Frequencies for first 10,000 rows of comstat4 variable in nhamcsed2007 dataset :

          for rx4, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      1,341       13.41       13.41
  combination drug |        249        2.49       15.90
                 . |      8,410       84.10      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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