Frequencies for first 10,000 rows of prescr3 variable in nhamcsopd2005 dataset :

 prescription status |
     code for med #3 |      Freq.     Percent        Cum.
---------------------+-----------------------------------
   prescription drug |      2,180       21.80       21.80
nonprescription drug |        339        3.39       25.19
        undetermined |        183        1.83       27.02
                   . |      7,298       72.98      100.00
---------------------+-----------------------------------
               Total |     10,000      100.00

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