Frequencies for first 10,000 rows of comstat6 variable in nhamcsopd2008 dataset :

          for rx6, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      1,480       14.80       14.80
  combination drug |        123        1.23       16.03
      undetermined |          1        0.01       16.04
                 . |      8,396       83.96      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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