Exhibit 99.24 MBNA MASTER CREDIT CARD TRUST II SERIES 1997-C KEY PERFORMANCE FACTORS August 31, 1999 Expected B Maturity 3/15/04 Blended Coupon 5.4289% Excess Protection Level 3 Month Average 5.75% August, 1999 5.97% July, 1999 6.06% June, 1999 5.22% Cash Yield 18.20% Investor Charge Offs 4.78% Base Rate 7.46% Over 30 Day Delinquency 4.81% Seller's Interest 7.19% Total Payment Rate 14.37% Total Principal Balance $46,158,397,644.87 Investor Participation Amount $750,000,000.00 Seller Participation Amount $3,316,578,126.38