Frequencies for first 10,000 rows of contsub5 variable in namcs2007 dataset :

    controlled status code |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
               schedule ii |         17        0.17        0.17
              schedule iii |         31        0.31        0.48
               schedule iv |         90        0.90        1.38
                schedule v |          9        0.09        1.47
                no control |      1,588       15.88       17.35
              undetermined |         34        0.34       17.69
                         . |      8,231       82.31      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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