Frequencies for first 10,000 rows of contsub1 variable in nhamcsopd2008 dataset :

       for rx1, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |        348        3.48        3.48
              schedule iii |        141        1.41        4.89
               schedule iv |        192        1.92        6.81
                schedule v |         23        0.23        7.04
                no control |      6,224       62.24       69.28
              undetermined |        141        1.41       70.69
                         8 |         30        0.30       70.99
                         . |      2,901       29.01      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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