Frequencies for first 10,000 rows of wtgn variable in linkco1991us_num dataset : Weight gain | Freq. Percent Cum. ------------+----------------------------------- 0 | 4,355 43.55 43.55 1 | 5,645 56.45 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015