For joint projects described in subdivision (2)(b) of section 72-2303, the principal amount of bonds which may be issued by a qualified public agency under the Public Facilities Construction and Finance Act shall not exceed two hundred fifty thousand dollars for cities of the metropolitan and primary classes, one hundred thousand dollars for counties, cities of the first class, school districts, educational service units, and community colleges, and fifty thousand dollars for cities of the second class and villages, as to the total principal amount of such bonds which may be outstanding at any time, and the annual amounts due by reason of such bonds from each qualified public agency shall not exceed five percent of the restricted funds of the obligated qualified public agency in the year prior to issuance. The principal amount of bonds of a qualified public agency in the aggregate issued for any one such joint project shall not exceed two hundred and fifty thousand dollars for cities of the metropolitan and primary classes and one hundred thousand dollars for counties, cities of the first class, cities of the second class, villages, school districts, educational service units, and community colleges.