Frequencies for first 10,000 rows of ca_cchd variable in natl2016 dataset :

   Cyanotic |
 Congenital |
      Heart |
  Disease Y |
        Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,994       99.94       99.94
          Y |          6        0.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 4 Oct 2017