Frequencies for first 10,000 rows of ca_gast variable in natlterr2007 dataset :

Gastroschis |
     is RFP |
640=f_ca_ga |
     stro R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      6,163       61.63       61.63
          N |      3,836       38.36       99.99
          U |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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