Frequencies for first 10,000 rows of contsub7 variable in nhamcsopd2009 dataset :

       for rx7, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         27        0.27        0.27
              schedule iii |         21        0.21        0.48
               schedule iv |         39        0.39        0.87
                schedule v |          3        0.03        0.90
                no control |      1,172       11.72       12.62
              undetermined |         13        0.13       12.75
        multiple schedules |          1        0.01       12.76
                         . |      8,724       87.24      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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