Frequencies for first 10,000 rows of contsub8 variable in nhamcsed2007 dataset :

       for rx8, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |          6        0.06        0.06
              schedule iii |          3        0.03        0.09
               schedule iv |          7        0.07        0.16
                schedule v |          1        0.01        0.17
                no control |        125        1.25        1.42
              undetermined |          4        0.04        1.46
                         . |      9,854       98.54      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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