Frequencies for first 10,000 rows of gestimp variable in natl1985 dataset : Gestation | Imputation | Flag | Freq. Percent Cum. ------------+----------------------------------- 1 | 1,720 17.20 17.20 . | 8,280 82.80 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 3 Jan 2016