Exhibit 99.40 MBNA MASTER CREDIT CARD TRUST II SERIES 1999-L KEY PERFORMANCE FACTORS March 31, 2001 Expected B Maturity 10/16/06 Blended Coupon 5.4970% Excess Protection Level 3 Month Average 7.38% March, 2001 7.97% February, 2001 7.35% January, 2001 6.80% Cash Yield20.67% Investor Charge Offs 4.83% Base Rate 7.86% Over 30 Day Delinquency 4.90% Seller's Interest 7.37% Total Payment Rate14.60% Total Principal Balance$56,622,749,044.91 Investor Participation Amount$750,000,000.00 Seller Participation Amount$4,172,058,483.42