Frequencies for first 10,000 rows of comstat5 variable in nhamcsed2006 dataset :

          for rx5, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |        454        4.54        4.54
  combination drug |         74        0.74        5.28
                 . |      9,472       94.72      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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