Frequencies for first 10,000 rows of contsub5 variable in nhamcsopd2007 dataset :

       for rx5, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         48        0.48        0.48
              schedule iii |         18        0.18        0.66
               schedule iv |         68        0.68        1.34
                schedule v |          5        0.05        1.39
                no control |      1,765       17.65       19.04
              undetermined |         30        0.30       19.34
                         . |      8,066       80.66      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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