Frequencies for first 10,000 rows of contsub4 variable in namcs2008 dataset :

    controlled status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         34        0.34        0.34
              schedule iii |         36        0.36        0.70
               schedule iv |        108        1.08        1.78
                schedule v |          7        0.07        1.85
                no control |      2,596       25.96       27.81
              undetermined |         28        0.28       28.09
        multiple schedules |          7        0.07       28.16
                         . |      7,184       71.84      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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