Frequencies for first 10,000 rows of tbskin variable in namcs1996 dataset : tb skin | test | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,958 99.58 99.58 1 | 42 0.42 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016