Frequencies for first 10,000 rows of contsub7 variable in namcs2008 dataset :

    controlled status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |          9        0.09        0.09
              schedule iii |         14        0.14        0.23
               schedule iv |         49        0.49        0.72
                schedule v |          7        0.07        0.79
                no control |        996        9.96       10.75
              undetermined |         20        0.20       10.95
        multiple schedules |          2        0.02       10.97
                         . |      8,903       89.03      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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