Frequencies for first 10,000 rows of f_clinest variable in natlterr2010 dataset : Clinical | Estimate of | Gestation | (estgest) | U;R | Freq. Percent Cum. ------------+----------------------------------- 0 | 1,246 12.46 12.46 1 | 8,754 87.54 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015