Frequencies for first 10,000 rows of contsub9 variable in nhamcsed2013 dataset :

      Controlled substance |
status code for medication |
                        #9 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               Schedule II |          6        0.06        0.06
              Schedule III |          3        0.03        0.09
               Schedule IV |          5        0.05        0.14
                No control |        161        1.61        1.75
                         . |      9,825       98.25      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 7 Nov 2016