Frequencies for first 10,000 rows of contsub8 variable in nhamcsed2008 dataset :

       for rx8, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |          8        0.08        0.08
              schedule iii |          9        0.09        0.17
               schedule iv |          6        0.06        0.23
                no control |        123        1.23        1.46
                         . |      9,854       98.54      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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