Frequencies for first 10,000 rows of tbskin variable in namcs1995 dataset : tb skin | test | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,937 99.37 99.37 1 | 63 0.63 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016