Frequencies for first 10,000 rows of contsub5 variable in nhamcsopd2008 dataset :

       for rx5, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         56        0.56        0.56
              schedule iii |         19        0.19        0.75
               schedule iv |         76        0.76        1.51
                schedule v |          9        0.09        1.60
                no control |      1,860       18.60       20.20
              undetermined |         19        0.19       20.39
                         . |      7,961       79.61      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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