Frequencies for first 10,000 rows of prescr1 variable in namcs2007 dataset :

 prescription status |
                code |      Freq.     Percent        Cum.
---------------------+-----------------------------------
   prescription drug |      6,779       67.79       67.79
nonprescription drug |        691        6.91       74.70
        undetermined |        229        2.29       76.99
                   . |      2,301       23.01      100.00
---------------------+-----------------------------------
               Total |     10,000      100.00

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