Frequencies for first 10,000 rows of contsub2 variable in namcs2007 dataset :

    controlled status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         97        0.97        0.97
              schedule iii |        111        1.11        2.08
               schedule iv |        191        1.91        3.99
                schedule v |         28        0.28        4.27
                no control |      4,614       46.14       50.41
              undetermined |        107        1.07       51.48
                         . |      4,852       48.52      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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