Frequencies for first 10,000 rows of comstat7 variable in nhamcsopd2007 dataset :

          for rx7, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      1,030       10.30       10.30
  combination drug |        112        1.12       11.42
                 . |      8,858       88.58      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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