Exhibit 99.21 MBNA MASTER CREDIT CARD TRUST II SERIES 1996-L KEY PERFORMANCE FACTORS MARCH, 1999 Expected B Maturity 12/15/99 Blended Coupon 5.0756% Excess Protection Level 3 Month Average 6.15% March, 1999 6.80% February, 1999 6.12% January, 1999 5.53% Cash Yield 19.20% Investor Charge Offs 5.12% Base Rate 7.27% Over 35 Day Delinquency 4.94% Seller's Interest 6.34% Total Payment Rate 14.77% Total Principal Balance $ 40,628,355,078.94 Investor Participation Amount $ 500,000,000.00 Seller Participation Amount $ 2,576,435,560.45