348. Where the total amount of expenses for the payment of which a tax must be levied exceeds 6% of the subsidies allocated by the Government to the school board for the year in which the tax is levied, less the subsidies for servicing the debt or for pupil transportation, or if the rate of the levying of the tax exceeds 25 cents per $100 of the standardized assessment of taxable immovables included in the real estate base of the school board, the tax is subject to the approval of the electors in accordance with sections 395 to 403.