Frequencies for first 10,000 rows of contsub4 variable in nhamcsopd2006 dataset :

       for rx4, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               Schedule II |         54        0.54        0.54
              Schedule III |         37        0.37        0.91
               Schedule IV |         99        0.99        1.90
                Schedule V |          4        0.04        1.94
                No control |      1,786       17.86       19.80
              Undetermined |         40        0.40       20.20
                         . |      7,980       79.80      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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