Frequencies for first 10,000 rows of catmri variable in nhamcsopd2000 dataset : catscan/mri | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,800 98.00 98.00 1 | 200 2.00 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016