Frequencies for first 10,000 rows of ab_seiz variable in natlterr2012 dataset :

   Seizures |
        RFP |
633=f_ab_se |
       iz R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      1,163       11.63       11.63
          N |      8,406       84.06       95.69
          U |        426        4.26       99.95
          Y |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 5 May 2016