Exhibit 99.31 MBNA MASTER CREDIT CARD TRUST II SERIES 1998-D KEY PERFORMANCE FACTORS March 31, 2000 Expected B Maturity 7/15/2003 Blended Coupon 5.8717% Excess Protection Level 3 Month Average 5.99% March, 2000 6.11% February, 2000 6.31% January, 2000 5.54% Cash Yield19.39% Investor Charge Offs 4.70% Base Rate 8.59% Over 30 Day Delinquency 4.65% Seller's Interest 8.73% Total Payment Rate15.20% Total Principal Balance$49,480,326,758.32 Investor Participation Amount$559,000,000.00 Seller Participation Amount$4,321,526,239.83