Frequencies for first 10,000 rows of comstat6 variable in nhamcsed2006 dataset :

          for rx6, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |        211        2.11        2.11
  combination drug |         29        0.29        2.40
                 . |      9,760       97.60      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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