Frequencies for first 10,000 rows of contsub20 variable in nhamcsed2014 dataset :

      Controlled substance |
status code for medication |
                       #20 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               Schedule II |          3        0.03        0.03
               Schedule IV |          1        0.01        0.04
                Schedule V |          1        0.01        0.05
                No control |         18        0.18        0.23
                         . |      9,977       99.77      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 11 Apr 2017