Frequencies for first 10,000 rows of breast variable in namcs2011 dataset : Breast exam | Freq. Percent Cum. ------------+----------------------------------- No | 9,669 96.69 96.69 Yes | 331 3.31 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016