Frequencies for first 10,000 rows of catscan variable in nhamcsed1995 dataset : cat scan | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,729 97.29 97.29 1 | 271 2.71 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016