Frequencies for first 10,000 rows of prescr7 variable in namcs2007 dataset :

 prescription status |
                code |      Freq.     Percent        Cum.
---------------------+-----------------------------------
   prescription drug |        812        8.12        8.12
nonprescription drug |         91        0.91        9.03
        undetermined |         27        0.27        9.30
                   . |      9,070       90.70      100.00
---------------------+-----------------------------------
               Total |     10,000      100.00

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