Frequencies for first 10,000 rows of contsub3 variable in nhamcsopd2006 dataset :

       for rx3, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               Schedule II |         77        0.77        0.77
              Schedule III |         72        0.72        1.49
               Schedule IV |        135        1.35        2.84
                Schedule V |         11        0.11        2.95
                No control |      2,584       25.84       28.79
              Undetermined |         62        0.62       29.41
                         . |      7,059       70.59      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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