Frequencies for first 10,000 rows of depress variable in nhamcsopd2009 dataset : depression | screening | Freq. Percent Cum. ------------+----------------------------------- no | 9,831 98.31 98.31 yes | 169 1.69 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016