Frequencies for first 10,000 rows of privins variable in nhamcsopd1994 dataset : expected | source of | payment-pri | vate/comm | insur | Freq. Percent Cum. ------------+----------------------------------- 0 | 8,262 82.62 82.62 1 | 1,738 17.38 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016