Frequencies for first 10,000 rows of contsub2 variable in nhamcsopd2008 dataset :

       for rx2, controlled |
     substance status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |        185        1.85        1.85
              schedule iii |         82        0.82        2.67
               schedule iv |        221        2.21        4.88
                schedule v |         15        0.15        5.03
                no control |      4,380       43.80       48.83
              undetermined |         79        0.79       49.62
                         8 |         14        0.14       49.76
                         . |      5,024       50.24      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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