Frequencies for first 10,000 rows of ab_seiz variable in natlterr2014 dataset :

 Seizures Y |
        Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      1,077       10.77       10.77
          N |      8,818       88.18       98.95
          U |         98        0.98       99.93
          Y |          7        0.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 15 Jun 2016