Frequencies for first 10,000 rows of comstat4 variable in nhamcsed2003 dataset :

composition status |
          code for |
     medication #4 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      1,261       12.61       12.61
  combination drug |        218        2.18       14.79
      undetermined |         43        0.43       15.22
                 . |      8,478       84.78      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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