Frequencies for first 10,000 rows of retappt variable in nhamcsopd1999 dataset : return to | clinic, | appt. | Freq. Percent Cum. ------------+----------------------------------- 0 | 3,473 34.73 34.73 1 | 6,527 65.27 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016