Frequencies for first 10,000 rows of retappt variable in nhamcsopd2008 dataset : return, | appt. | Freq. Percent Cum. ------------+----------------------------------- no | 2,502 25.02 25.02 yes | 7,498 74.98 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016