Frequencies for first 10,000 rows of contsub7 variable in namcs2009 dataset :

    controlled status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         20        0.20        0.20
              schedule iii |         13        0.13        0.33
               schedule iv |         50        0.50        0.83
                schedule v |          5        0.05        0.88
                no control |      1,141       11.41       12.29
              undetermined |         24        0.24       12.53
        multiple schedules |          2        0.02       12.55
                         . |      8,745       87.45      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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