Frequencies for first 10,000 rows of contsub4 variable in namcs2009 dataset :

    controlled status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         40        0.40        0.40
              schedule iii |         37        0.37        0.77
               schedule iv |        125        1.25        2.02
                schedule v |         13        0.13        2.15
                no control |      2,721       27.21       29.36
              undetermined |         34        0.34       29.70
        multiple schedules |          4        0.04       29.74
                         . |      7,026       70.26      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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