Frequencies for first 10,000 rows of uld_cephal variable in natl2005 dataset :

Cephalopelv |
         ic |
Disproporti |
       on U |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        179        1.79        1.79
          2 |      9,702       97.02       98.81
          9 |        119        1.19      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015