Cities are hereby empowered to establish a "Capital Improvements Fund", by ordinance, and levy a special tax not to exceed in the aggregate four-hundredths per cent (.04%) of market value for assessment purposes in any one (1) year. Said fund shall never exceed in the aggregate four-tenths per cent (.4%) of the market value for assessment purposes of the city. Such funds shall not be subject to the provisions of section 50-1014, Idaho Code. Said ordinance shall identify the specific purpose for which the capital improvements fund shall be used.