Frequencies for first 10,000 rows of ab_seiz variable in natl2013 dataset :

   Seizures |
        RFP |
633=f_ab_se |
       iz R |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,681       96.81       96.81
          U |        310        3.10       99.91
          Y |          9        0.09      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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