Frequencies for first 10,000 rows of mri variable in nhamcsopd2008 dataset : mri | Freq. Percent Cum. ------------+----------------------------------- no | 9,815 98.15 98.15 yes | 185 1.85 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016