Frequencies for first 10,000 rows of comstat7 variable in nhamcsed2011 dataset :

Composition status |
          code for |
     medication #7 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        299        2.99        2.99
  Combination drug |         35        0.35        3.34
      Undetermined |          2        0.02        3.36
                 . |      9,664       96.64      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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