The rating on New Jersey Educational Facilities Authority's bonds, issued for Middlesex County, N.J., is based on the underlying creditworthiness of the county and reflects: A diverse and growing economic base, Above-average wealth and income levels, Strong financial performance and position, and Manageable debt burden. The bonds are secured by revenues received by the authority from loan repayments made by the county pursuant to a bond purchase agreement. Under that agreement, the authority will loan the proceeds of the bonds to Middlesex County, who in turn will issue county bonds to the authority in a sufficient amount and amortization schedule as to repay the authority bonds in a timely manner. The loan repayments are made in advance of the debt