Frequencies for first 10,000 rows of comstat4 variable in nhamcsed2006 dataset :

          for rx4, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      1,031       10.31       10.31
  combination drug |        197        1.97       12.28
                 . |      8,772       87.72      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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