Frequencies for first 10,000 rows of contsub1 variable in nhamcsopd2006 dataset :

       for rx1, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               Schedule II |        301        3.01        3.01
              Schedule III |        163        1.63        4.64
               Schedule IV |        184        1.84        6.48
                Schedule V |         15        0.15        6.63
                No control |      5,823       58.23       64.86
              Undetermined |        194        1.94       66.80
                         . |      3,320       33.20      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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