Frequencies for first 10,000 rows of contsub1 variable in nhamcsed2003 dataset :

 controlled substance code |
         for medication #1 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |        605        6.05        6.05
              schedule iii |        562        5.62       11.67
               schedule iv |        248        2.48       14.15
                schedule v |         20        0.20       14.35
                no control |      6,106       61.06       75.41
              undetermined |        160        1.60       77.01
                         . |      2,299       22.99      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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