Frequencies for first 10,000 rows of f_clinest variable in natlterr2005 dataset : Clinical | Estimate of | Gestation | U;R | Freq. Percent Cum. ------------+----------------------------------- 0 | 1,741 17.41 17.41 1 | 8,259 82.59 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015