Frequencies for first 10,000 rows of contsub2 variable in namcs2009 dataset :

    controlled status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |        120        1.20        1.20
              schedule iii |         93        0.93        2.13
               schedule iv |        233        2.33        4.46
                schedule v |         23        0.23        4.69
                no control |      5,032       50.32       55.01
              undetermined |         98        0.98       55.99
        multiple schedules |         28        0.28       56.27
                         . |      4,373       43.73      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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