Frequencies for first 10,000 rows of contsub8 variable in nhamcsopd2003 dataset :

 controlled substance code |
         for medication #8 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         17        0.17        0.17
              schedule iii |          6        0.06        0.23
               schedule iv |         24        0.24        0.47
                no control |        478        4.78        5.25
              undetermined |         15        0.15        5.40
                         . |      9,460       94.60      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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