Frequencies for first 10,000 rows of contsub6 variable in namcs2009 dataset :

    controlled status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         22        0.22        0.22
              schedule iii |         25        0.25        0.47
               schedule iv |         62        0.62        1.09
                schedule v |          7        0.07        1.16
                no control |      1,531       15.31       16.47
              undetermined |         33        0.33       16.80
        multiple schedules |          3        0.03       16.83
                         . |      8,317       83.17      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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