Frequencies for first 10,000 rows of cardiac variable in natlterr2000 dataset : Cardiac | disease | Freq. Percent Cum. ------------+----------------------------------- 1 | 27 0.27 0.27 2 | 9,972 99.72 99.99 9 | 1 0.01 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015