Frequencies for first 10,000 rows of comstat2 variable in namcs2006 dataset :

          for rx2, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      4,353       43.53       43.53
  combination drug |        783        7.83       51.36
                 . |      4,864       48.64      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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