Frequencies for first 10,000 rows of ca_omph variable in natlterr2006 dataset :

Omphalocele |
        RFP |
639=f_ca_om |
      pha R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      6,275       62.75       62.75
          N |      3,724       37.24       99.99
          Y |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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