Frequencies for first 10,000 rows of ca_downs variable in natlterr2008 dataset :

      Downs |
   Syndrome |
        RFP |
644=f_ca_do |
      wns R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      6,061       60.61       60.61
          C |          2        0.02       60.63
          N |      3,933       39.33       99.96
          P |          4        0.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 May 2016