Frequencies for first 10,000 rows of contsub6 variable in nhamcsopd2003 dataset :

 controlled substance code |
         for medication #6 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         33        0.33        0.33
              schedule iii |         21        0.21        0.54
               schedule iv |         37        0.37        0.91
                schedule v |          2        0.02        0.93
                no control |        833        8.33        9.26
              undetermined |         30        0.30        9.56
                         . |      9,044       90.44      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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