Frequencies for first 10,000 rows of bcbs variable in nhamcsopd1996 dataset : blue | cross/blue | shield | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,024 90.24 90.24 1 | 976 9.76 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016