Frequencies for first 10,000 rows of contsub1 variable in nhamcsopd2003 dataset :

 controlled substance code |
         for medication #1 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |        268        2.68        2.68
              schedule iii |         96        0.96        3.64
               schedule iv |        183        1.83        5.47
                schedule v |         10        0.10        5.57
                no control |      5,372       53.72       59.29
              undetermined |        207        2.07       61.36
                         . |      3,864       38.64      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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