Frequencies for first 10,000 rows of mammo variable in namcs2014 dataset :

Mammography |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,789       97.89       97.89
        Yes |        211        2.11      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 27 Mar 2017