Frequencies for first 10,000 rows of contsub3 variable in nhamcsopd2009 dataset :

       for rx3, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |        105        1.05        1.05
              schedule iii |         49        0.49        1.54
               schedule iv |        147        1.47        3.01
                schedule v |          6        0.06        3.07
                no control |      3,238       32.38       35.45
              undetermined |         53        0.53       35.98
        multiple schedules |          9        0.09       36.07
                         . |      6,393       63.93      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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