Frequencies for first 10,000 rows of comstat6 variable in nhamcsed2004 dataset :

composition status |
          code for |
     medication #6 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |        649        6.49        6.49
  combination drug |         73        0.73        7.22
      undetermined |         17        0.17        7.39
                 . |      9,261       92.61      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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