Frequencies for first 10,000 rows of prescr1 variable in nhamcsopd2006 dataset :

            for rx1, |
 prescription status |
                code |      Freq.     Percent        Cum.
---------------------+-----------------------------------
   Prescription drug |      5,424       54.24       54.24
Nonprescription drug |        796        7.96       62.20
        Undetermined |        460        4.60       66.80
                   . |      3,320       33.20      100.00
---------------------+-----------------------------------
               Total |     10,000      100.00

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