Frequencies for first 10,000 rows of contsub7 variable in nhamcsed2003 dataset :

 controlled substance code |
         for medication #7 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         17        0.17        0.17
              schedule iii |         14        0.14        0.31
               schedule iv |         12        0.12        0.43
                no control |        286        2.86        3.29
              undetermined |         17        0.17        3.46
                         . |      9,654       96.54      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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