Frequencies for first 10,000 rows of ca_down variable in natlterr2006 dataset :

      Downs |
   Syndrome |
        RFP |
644=f_ca_do |
      wns R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      6,275       62.75       62.75
          N |      3,720       37.20       99.95
          P |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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