Frequencies for first 10,000 rows of comstat2 variable in nhamcsed2007 dataset :

          for rx2, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      4,361       43.61       43.61
  combination drug |        814        8.14       51.75
                 . |      4,825       48.25      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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