Frequencies for first 10,000 rows of hearing variable in nhamcsopd1999 dataset : hearing | exam | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,701 97.01 97.01 1 | 299 2.99 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016