Frequencies for first 10,000 rows of contsub3 variable in nhamcsopd2004 dataset :

 controlled substance code |
         for medication #3 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         72        0.72        0.72
              schedule iii |         30        0.30        1.02
               schedule iv |        104        1.04        2.06
                schedule v |          6        0.06        2.12
                no control |      2,401       24.01       26.13
              undetermined |         71        0.71       26.84
                         . |      7,316       73.16      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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