Exhibit 99.31 MBNA MASTER CREDIT CARD TRUST II SERIES 1997-K KEY PERFORMANCE FACTORS June 30, 1998 Expected B Maturity 11/15/2005 Blended Coupon 5.8331% Excess Protection Level 3 Month Average 5.16% June, 1998 4.70% May, 1998 4.93% April, 1998 5.87% Cash Yield 17.67% Investor Charge Offs 5.10% Base Rate 7.86% Over 35 Day Delinquency 5.06% Seller's Interest 12.61% Total Payment Rate 13.35% Total Principal Balance $35,974,950,178.51 Investor Participation Amount $750,000,000.00 Seller Participation Amount $4,536,555,660.02