Frequencies for first 10,000 rows of medicare variable in nhamcsopd1992 dataset : Expected | source of | payment-Med | icare | Freq. Percent Cum. ------------+----------------------------------- 0 | 8,592 85.92 85.92 1 | 1,408 14.08 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016