The state tax commission shall apportion the aggregate value of all distributable property herein specified, which is owned, used, leased or otherwise controlled by each railroad company, to each county, municipal township, city or incorporated town, special road districts, library districts, school districts which levy taxes for library purposes pursuant to section 137.030, hospital districts, nursing home districts, ambulance districts, metropolitan zoological park and museum district established pursuant to section 184.350, public water supply, fire protection and sewer districts or subdivisions, except other school districts, in which the road is located, according to the ratio which the number of miles of the road completed in the county, municipal township, city or incorporated town, special road district, library districts, school districts which levy taxes for library purposes pursuant to section 137.030, hospital districts, nursing home districts, ambulance districts, metropolitan zoological park and museum district established pursuant to section 184.350, public water supply, fire protection and sewer districts or subdivisions, except other school districts, in which the road is located shall bear to the whole length of the road in this state; provided, that in any case where a company whose line or road is liable to taxation shall have been or may become consolidated into another corporation, entitled by its charter or otherwise to exemption from county or other taxation, that portion of the road which is liable to taxation, as aforesaid, shall be assessed separately, and the value thereof apportioned to the counties, municipal townships, cities or incorporated towns, special road districts, library districts, school districts which levy taxes for library purposes pursuant to section 137.030, hospital districts, nursing home districts, ambulance districts, metropolitan zoological park and museum district established pursuant to section 184.350, public water supply, fire protection and sewer districts or subdivisions, except other school districts, in which it is located; and an authorized officer of each such railroad company shall, in the annual reports rendered to the state tax commission, as provided in section 151.020, include statement of the length of the road within school districts which levy taxes for library purposes pursuant to section 137.030, and library districts; provided, further, that in no event shall any school district levy school taxes, taxes for the erection of public buildings, or for other purposes except library purposes on the property herein specified, in any manner other than that provided for in section 151.150.