Frequencies for first 10,000 rows of contsub6 variable in nhamcsed2004 dataset :

 controlled substance code |
         for medication #6 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         33        0.33        0.33
              schedule iii |         16        0.16        0.49
               schedule iv |         27        0.27        0.76
                schedule v |          2        0.02        0.78
                no control |        642        6.42        7.20
              undetermined |         19        0.19        7.39
                         . |      9,261       92.61      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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