Frequencies for first 10,000 rows of contsub4 variable in nhamcsed2003 dataset :

 controlled substance code |
         for medication #4 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |        102        1.02        1.02
              schedule iii |         80        0.80        1.82
               schedule iv |         62        0.62        2.44
                schedule v |          9        0.09        2.53
                no control |      1,226       12.26       14.79
              undetermined |         43        0.43       15.22
                         . |      8,478       84.78      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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