Frequencies for first 10,000 rows of ca_cleft variable in natl2015 dataset :

  Cleft Lip |
  w/ or w/o |
      Cleft |
   Palate Y |
        Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,987       99.87       99.87
          U |          1        0.01       99.88
          Y |         12        0.12      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Oct 2016