Frequencies for first 10,000 rows of prescr2 variable in namcs2006 dataset :

            for rx2, |
 prescription status |
                code |      Freq.     Percent        Cum.
---------------------+-----------------------------------
   prescription drug |      4,337       43.37       43.37
nonprescription drug |        456        4.56       47.93
        undetermined |        343        3.43       51.36
                   . |      4,864       48.64      100.00
---------------------+-----------------------------------
               Total |     10,000      100.00

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