Frequencies for first 10,000 rows of gestimp variable in natl1997 dataset : Gestation | Imputation | Flag | Freq. Percent Cum. ------------+----------------------------------- 1 | 1,271 12.71 12.71 . | 8,729 87.29 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015