Frequencies for first 10,000 rows of contsub6 variable in nhamcsopd2006 dataset :

       for rx6, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               Schedule II |         21        0.21        0.21
              Schedule III |         23        0.23        0.44
               Schedule IV |         30        0.30        0.74
                Schedule V |          3        0.03        0.77
                No control |        964        9.64       10.41
              Undetermined |         13        0.13       10.54
                         . |      8,946       89.46      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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