Exhibit 99.31 MBNA MASTER CREDIT CARD TRUST II SERIES 1998-D KEY PERFORMANCE FACTORS April 30, 2000 Expected B Maturity 7/15/2003 Blended Coupon 5.8811% Excess Protection Level 3 Month Average 6.01% April, 2000 5.61% March, 2000 6.11% February, 2000 6.31% Cash Yield18.08% Investor Charge Offs 4.70% Base Rate 7.77% Over 30 Day Delinquency 4.72% Seller's Interest10.74% Total Payment Rate13.82% Total Principal Balance$52,271,464,953.72 Investor Participation Amount$559,000,000.00 Seller Participation Amount$5,612,664,435.23