Frequencies for first 10,000 rows of gestimp variable in natl1988 dataset : Gestation | Imputation | Flag | Freq. Percent Cum. ------------+----------------------------------- 1 | 1,475 14.75 14.75 . | 8,525 85.25 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 3 Jan 2016