Frequencies for first 10,000 rows of cleftlp variable in natl2001 dataset : Cleft | lip/palate | Freq. Percent Cum. ------------+----------------------------------- 1 | 6 0.06 0.06 2 | 9,992 99.92 99.98 8 | 1 0.01 99.99 9 | 1 0.01 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015