Exhibit 99.41 MBNA MASTER CREDIT CARD TRUST II SERIES 1999-B KEY PERFORMANCE FACTORS June 30, 1999 Expected B Maturity 3/16/2009 Blended Coupon 5.9788% Excess Protection Level 3 Month Average 5.29% June, 1999 5.07% May, 1999 7.20% April, 1999 3.62% Cash Yield17.44% Investor Charge Offs 5.06% Base Rate 7.30% Over 30 Day Delinquency 4.82% Seller's Interest11.01% Total Payment Rate13.71% Total Principal Balance$44,380,968,357.42 Investor Participation Amount$750,000,000.00 Seller Participation Amount$4,888,448,838.93