Frequencies for first 10,000 rows of contsub8 variable in nhamcsopd2007 dataset :

       for rx8, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         12        0.12        0.12
              schedule iii |         16        0.16        0.28
               schedule iv |         35        0.35        0.63
                schedule v |          3        0.03        0.66
                no control |        761        7.61        8.27
              undetermined |         17        0.17        8.44
                         . |      9,156       91.56      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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