Frequencies for first 10,000 rows of comstat8 variable in nhamcsed2005 dataset :

composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |        113        1.13        1.13
  combination drug |         10        0.10        1.23
      undetermined |          1        0.01        1.24
                 . |      9,876       98.76      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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