Frequencies for first 10,000 rows of contsub1 variable in namcs2007 dataset :

    controlled status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |        213        2.13        2.13
              schedule iii |        146        1.46        3.59
               schedule iv |        243        2.43        6.02
                schedule v |         33        0.33        6.35
                no control |      6,868       68.68       75.03
              undetermined |        196        1.96       76.99
                         . |      2,301       23.01      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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