Frequencies for first 10,000 rows of contsub7 variable in nhamcsed2004 dataset :

 controlled substance code |
         for medication #7 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         17        0.17        0.17
              schedule iii |          7        0.07        0.24
               schedule iv |         22        0.22        0.46
                schedule v |          1        0.01        0.47
                no control |        447        4.47        4.94
              undetermined |         16        0.16        5.10
                         . |      9,490       94.90      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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