Frequencies for first 10,000 rows of prescr4 variable in nhamcsopd2005 dataset :

 prescription status |
     code for med #4 |      Freq.     Percent        Cum.
---------------------+-----------------------------------
   prescription drug |      1,393       13.93       13.93
nonprescription drug |        219        2.19       16.12
        undetermined |        120        1.20       17.32
                   . |      8,268       82.68      100.00
---------------------+-----------------------------------
               Total |     10,000      100.00

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