Frequencies for first 10,000 rows of contsub3 variable in nhamcsopd2011 dataset :

      Controlled substance |
status code for Medication |
                        #3 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               Schedule II |         77        0.77        0.77
              Schedule III |         12        0.12        0.89
               Schedule IV |        141        1.41        2.30
                Schedule V |          8        0.08        2.38
                No control |      3,375       33.75       36.13
              Undetermined |         35        0.35       36.48
        Multiple schedules |          8        0.08       36.56
                         . |      6,344       63.44      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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