Frequencies for first 10,000 rows of comstat1 variable in nhamcsed2007 dataset :

          for rx1, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      6,414       64.14       64.14
  combination drug |      1,352       13.52       77.66
                 . |      2,234       22.34      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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