Frequencies for first 10,000 rows of prescr3 variable in nhamcsed2006 dataset :

            for rx3, |
 prescription status |
                code |      Freq.     Percent        Cum.
---------------------+-----------------------------------
   prescription drug |      1,850       18.50       18.50
nonprescription drug |        346        3.46       21.96
        undetermined |        260        2.60       24.56
                   . |      7,544       75.44      100.00
---------------------+-----------------------------------
               Total |     10,000      100.00

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