Frequencies for first 10,000 rows of contsub8 variable in namcs2007 dataset :

    controlled status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |          8        0.08        0.08
              schedule iii |          8        0.08        0.16
               schedule iv |         26        0.26        0.42
                schedule v |          4        0.04        0.46
                no control |        605        6.05        6.51
              undetermined |          7        0.07        6.58
                         . |      9,342       93.42      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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