Frequencies for first 10,000 rows of ca_down variable in natlterr2005 dataset :

      Downs |
 Syndrome R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      6,255       62.55       62.55
          C |          1        0.01       62.56
          N |      3,738       37.38       99.94
          P |          6        0.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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