Frequencies for first 10,000 rows of contsub5 variable in namcs2009 dataset :

    controlled status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         34        0.34        0.34
              schedule iii |         35        0.35        0.69
               schedule iv |         99        0.99        1.68
                schedule v |          8        0.08        1.76
                no control |      2,015       20.15       21.91
              undetermined |         48        0.48       22.39
        multiple schedules |          3        0.03       22.42
                         . |      7,758       77.58      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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