Frequencies for first 10,000 rows of contsub2 variable in nhamcsed2003 dataset :

 controlled substance code |
         for medication #2 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |        315        3.15        3.15
              schedule iii |        316        3.16        6.31
               schedule iv |        184        1.84        8.15
                schedule v |         27        0.27        8.42
                no control |      4,031       40.31       48.73
              undetermined |        115        1.15       49.88
                         . |      5,012       50.12      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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