Frequencies for first 10,000 rows of comstat2 variable in nhamcsed2006 dataset :

          for rx2, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      4,078       40.78       40.78
  combination drug |        761        7.61       48.39
                 . |      5,161       51.61      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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