Frequencies for first 10,000 rows of prescr2 variable in nhamcsed2005 dataset :

 prescription status |
                code |      Freq.     Percent        Cum.
---------------------+-----------------------------------
   prescription drug |      3,793       37.93       37.93
nonprescription drug |        707        7.07       45.00
        undetermined |        569        5.69       50.69
                   . |      4,931       49.31      100.00
---------------------+-----------------------------------
               Total |     10,000      100.00

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