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

      Downs |
   Syndrome |
        RFP |
644=f_ca_do |
      wns R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      6,163       61.63       61.63
          C |          2        0.02       61.65
          N |      3,828       38.28       99.93
          P |          6        0.06       99.99
          U |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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