Frequencies for first 10,000 rows of gestimp variable in natl1991 dataset : Gestation | Imputation | Flag | Freq. Percent Cum. ------------+----------------------------------- 1 | 1,521 15.21 15.21 . | 8,479 84.79 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015