Frequencies for first 10,000 rows of contsub3 variable in nhamcsed2008 dataset :

       for rx3, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |        308        3.08        3.08
              schedule iii |        192        1.92        5.00
               schedule iv |        103        1.03        6.03
                schedule v |          5        0.05        6.08
                no control |      2,406       24.06       30.14
              undetermined |         71        0.71       30.85
        multiple schedules |         24        0.24       31.09
                         . |      6,891       68.91      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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