Exhibit 99.43 MBNA MASTER CREDIT CARD TRUST II SERIES 1999-L KEY PERFORMANCE FACTORS August 31, 2000 Expected B Maturity 10/16/06 Blended Coupon 6.9520% Excess Protection Level 3 Month Average 5.36% August, 2000 5.42% July, 2000 5.92% June, 2000 4.74% Cash Yield19.12% Investor Charge Offs 4.51% Base Rate 9.18% Over 30 Day Delinquency 4.84% Seller's Interest10.94% Total Payment Rate14.32% Total Principal Balance$55,220,806,818.68 Investor Participation Amount$750,000,000.00 Seller Participation Amount$6,039,606,300.19