Frequencies for first 10,000 rows of contsub6 variable in namcs2006 dataset :

       for rx6, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         12        0.12        0.12
              schedule iii |         18        0.18        0.30
               schedule iv |         50        0.50        0.80
                schedule v |          4        0.04        0.84
                no control |      1,122       11.22       12.06
              undetermined |         29        0.29       12.35
                         . |      8,765       87.65      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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