Frequencies for first 10,000 rows of comstat1 variable in nhamcsed2006 dataset :

          for rx1, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      6,360       63.60       63.60
  combination drug |      1,349       13.49       77.09
                 . |      2,291       22.91      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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