Frequencies for first 10,000 rows of contsub12 variable in nhamcsed2012 dataset :

      Controlled substance |
status code for medication |
                       #12 |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               Schedule IV |          2        0.02        0.02
                No control |         12        0.12        0.14
                         . |      9,986       99.86      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 7 Nov 2016