Frequencies for first 10,000 rows of cephalo variable in natl2001 dataset :

Cephalopelv |
         ic |
disproporti |
         on |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        234        2.34        2.34
          2 |      9,764       97.64       99.98
          8 |          1        0.01       99.99
          9 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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