Frequencies for first 10,000 rows of contsub7 variable in nhamcsopd2003 dataset :

 controlled substance code |
         for medication #7 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         23        0.23        0.23
              schedule iii |         14        0.14        0.37
               schedule iv |         22        0.22        0.59
                schedule v |          1        0.01        0.60
                no control |        635        6.35        6.95
              undetermined |         27        0.27        7.22
                         . |      9,278       92.78      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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