Frequencies for first 10,000 rows of prescr3 variable in namcs2006 dataset :

            for rx3, |
 prescription status |
                code |      Freq.     Percent        Cum.
---------------------+-----------------------------------
   prescription drug |      2,921       29.21       29.21
nonprescription drug |        285        2.85       32.06
        undetermined |        221        2.21       34.27
                   . |      6,573       65.73      100.00
---------------------+-----------------------------------
               Total |     10,000      100.00

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