Frequencies for first 10,000 rows of uca_ompha variable in natl2014 dataset :

Omphalocele |
          / |
Gastroschis |
       is 1 |
    Anomaly |
   reported |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          9        0.09        0.09
          2 |      9,991       99.91      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 15 Jun 2016