Frequencies for first 10,000 rows of contsub3 variable in namcs2008 dataset :

    controlled status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         49        0.49        0.49
              schedule iii |         71        0.71        1.20
               schedule iv |        162        1.62        2.82
                schedule v |         18        0.18        3.00
                no control |      3,625       36.25       39.25
              undetermined |         42        0.42       39.67
        multiple schedules |         13        0.13       39.80
                         . |      6,020       60.20      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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