Exhibit 99.21 MBNA MASTER CREDIT CARD TRUST II SERIES 1997-C KEY PERFORMANCE FACTORS May 31, 2000 Expected B Maturity 3/15/04 Blended Coupon 6.6814% Excess Protection Level 3 Month Average 5.72% May, 2000 5.69% April, 2000 5.51% March, 2000 5.95% Cash Yield 19.29% Investor Charge Offs 4.66% Base Rate 8.94% Over 30 Day Delinquency 4.70% Seller's Interest 9.50% Total Payment Rate 14.38% Total Principal Balance $52,496,626,963.52 Investor Participation Amount $750,000,000.00 Seller Participation Amount $4,987,826,445.03