Exhibit 99.40 MBNA MASTER CREDIT CARD TRUST II SERIES 1999-E KEY PERFORMANCE FACTORS May 31, 2000 Expected B Maturity 06/17/2002 Blended Coupon 6.7053% Excess Protection Level 3 Month Average 5.70% May, 2000 5.70% April, 2000 5.49% March, 2000 5.89% Cash Yield19.29% Investor Charge Offs 4.66% Base Rate 8.93% Over 30 Day Delinquency 4.70% Seller's Interest 9.50% Total Payment Rate14.38% Total Principal Balance$52,496,626,963.52 Investor Participation Amount$1,000,000,000.00 Seller Participation Amount$4,987,826,445.03