Except as otherwise provided in sections 18A:24-20 to 18A:24-27, no bonds shall be authorized for the purposes of any school district if the principal amount thereof shall, when added to the net school debt of the district exceed the percentage of the average equalized valuation of taxable property in such district as herein provided:
through grade 6................. 2 1/2%
Each school district prior to the issuance of bonds shall secure from the State Commissioner of Education a certificate of the grade levels of instruction provided or to be provided by said school district.
Provided, however, that except as otherwise provided in sections 18A:24-20 to 18A:24-27, bonds may be authorized for the purposes of a school district in a city of the first class if the principal amount thereof shall, when added to the net school debt of the district, not exceed 8% of the average equalized valuation of taxable property in such district.
Further provided, that except as otherwise provided in sections 18A:24-20 to 18A:24-27, bonds may be authorized for the purposes of a school district in a city of the second class with a population in excess of 80,000, according to the latest federal decennial census if the principal amount thereof shall, when added to the net school debt of the district, not exceed 6% of the average equalized valuation of taxable property in such district.
N.J.S. § 18A:24-19