Frequencies for first 10,000 rows of contsub3 variable in nhamcsopd2007 dataset :

       for rx3, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         70        0.70        0.70
              schedule iii |         57        0.57        1.27
               schedule iv |        107        1.07        2.34
                schedule v |         13        0.13        2.47
                no control |      3,045       30.45       32.92
              undetermined |         61        0.61       33.53
                         . |      6,647       66.47      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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