Frequencies for first 10,000 rows of contsub1 variable in nhamcsed2008 dataset :

       for rx1, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |        756        7.56        7.56
              schedule iii |        546        5.46       13.02
               schedule iv |        290        2.90       15.92
                schedule v |         12        0.12       16.04
                no control |      6,033       60.33       76.37
              undetermined |        141        1.41       77.78
        multiple schedules |         59        0.59       78.37
                         . |      2,163       21.63      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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