Frequencies for first 10,000 rows of educm variable in linkco1991us_num dataset : Education | of mother | Freq. Percent Cum. ------------+----------------------------------- 0 | 20 0.20 0.20 1 | 9,980 99.80 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015