Frequencies for first 10,000 rows of breast variable in namcs1999 dataset :

breast exam |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,493       94.93       94.93
          1 |        507        5.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016