Exhibit 99.21 MBNA MASTER CREDIT CARD TRUST II SERIES 1997-C KEY PERFORMANCE FACTORS March 31, 2000 Expected B Maturity 3/15/04 Blended Coupon 6.1642% Excess Protection Level 3 Month Average 5.86% March, 2000 5.95% February, 2000 6.21% January, 2000 5.42% Cash Yield 19.39% Investor Charge Offs 4.70% Base Rate 8.75% Over 30 Day Delinquency 4.65% Seller's Interest 8.73% Total Payment Rate 15.20% Total Principal Balance $49,480,326,758.32 Investor Participation Amount $750,000,000.00 Seller Participation Amount $4,321,526,239.83