The County has participated in several issues of industrial and single family mortgage revenue bonds issued for the purpose of constructing privately operated facilities within the County. These bonds are not direct or contingent liabilities of the County. Revenues from the facilities constructed with bond proceeds are pledged for the total payment of principal and interest on the bonds and the bondholders can look only to these sources for repayment. As of December 31, 1997, there were seven series of industrial revenue bonds and four series of single family mortgage revenue bonds outstanding. The principal amount payable for the one series issued after January 1, 1996 was $3.2 million. The original issue amount of bonds issued prior to 1996 was $54.3 million.