Frequencies for first 10,000 rows of ca_down variable in natlterr2010 dataset :

      Downs |
   Syndrome |
        RFP |
644=f_ca_do |
      wns R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      4,656       46.56       46.56
          C |          3        0.03       46.59
          N |      4,363       43.63       90.22
          P |          5        0.05       90.27
          U |        973        9.73      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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