Exhibit 99.21 MBNA MASTER CREDIT CARD TRUST II SERIES 1996-K KEY PERFORMANCE FACTORS September 30, 1997 Expected B Maturity 11/17/03 Blended Coupon 5.8380% Excess Protection Level 3 Month Average 4.65% September, 1997 4.79% August, 1997 4.62% July, 1997 4.55% Cash Yield 17.46% Investor Charge Offs 4.80% Base Rate 7.87% Over 35 Day Delinquency 4.84% Seller's Interest 12.31% Total Payment Rate 12.46% Total Principal Balance $30,549,822,447.26 Investor Participation Amount $1,000,000,000.00 Seller Participation Amount $3,759,687,928.77