Exhibit 99.24 MBNA MASTER CREDIT CARD TRUST II SERIES 1997-B KEY PERFORMANCE FACTORS September 30, 1997 Expected B Maturity 3/15/12 Blended Coupon 5.8898% Excess Protection Level 3 Month Average 4.60% September, 1997 4.77% August, 1997 4.54% July, 1997 4.50% Cash Yield 17.46% Investor Charge Offs 4.80% Base Rate 7.89% 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