Frequencies for first 10,000 rows of comstat3 variable in nhamcsed2007 dataset :

          for rx3, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      2,540       25.40       25.40
  combination drug |        481        4.81       30.21
                 . |      6,979       69.79      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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