Frequencies for first 10,000 rows of ca_cchd variable in natlterr2015 dataset :

   Cyanotic |
 Congenital |
      Heart |
  Disease Y |
        Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      1,078       10.78       10.78
          N |      8,802       88.02       98.80
          U |        114        1.14       99.94
          Y |          6        0.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Oct 2016