At the end of each fiscal year, if any amount shall have accrued from taxation or revenue received from dividends or stocks or surplus receipts or earnings from any source, which are now or will be hereafter pledged to be applied to interest and sinking fund for the protection of all classes of outstanding bonds, or to be hereinafter issued, to exceed two (2) per cent for sinking fund, then in that event, the surplus, if any, over and above the two (2) per cent sinking fund, can be used for the purpose of making general improvements, or otherwise, as the council may determine.