Frequencies for first 10,000 rows of contsub8 variable in namcs2010 dataset :

    controlled status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         11        0.11        0.11
              schedule iii |         11        0.11        0.22
               schedule iv |         27        0.27        0.49
                schedule v |          3        0.03        0.52
                no control |        780        7.80        8.32
              undetermined |          8        0.08        8.40
        multiple schedules |          1        0.01        8.41
                         . |      9,159       91.59      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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