Every railroad company owning or operating a line of railroad within this state shall, on or before the first day of August 1902, place on file in the office of the county auditor of each county in the state into which any part of the lines of any said company lies, a plat of the lines of said companies within said county, showing the length of their said lines and the area of the land owned or occupied by said companies in each government subdivision of land not included within the platted portion of any city, within each of said counties, and the length of the said lines within the platted portion of cities. Companies having on file such plats of part or all of their lines, in any of said counties, shall be required to file plats only of that part of their lines not fully shown as above required on the plats now on file. On the first day of January of each year, like plats shall be filed of all new lines or extensions of existing lines built or completed within the calendar year preceding.