Frequencies for first 10,000 rows of ca_gast variable in natl2017 dataset :

Gastroschis |
   is Y Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,990       99.90       99.90
          Y |         10        0.10      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 19 Sep 2018