Frequencies for first 10,000 rows of prescr2 variable in nhamcsed2007 dataset :

            for rx2, |
 prescription status |
                code |      Freq.     Percent        Cum.
---------------------+-----------------------------------
   prescription drug |      4,135       41.35       41.35
nonprescription drug |        963        9.63       50.98
        undetermined |         77        0.77       51.75
                   . |      4,825       48.25      100.00
---------------------+-----------------------------------
               Total |     10,000      100.00

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