All assessments for local improvements made or levied by the proper authorities of any municipality in the state now or hereafter having a population of over 50,000, and bid in by any such municipality on or subsequent to the first day of January, 1908, or which may hereafter be made or levied and bid in by any such municipality, shall be of equal rank with the lien of the state for general taxes which have been or may hereafter be levied upon the property under the general laws of the state, so long as the liens for local improvements or the liens for general taxes continue to be held and owned by the state or any such municipality, respectively, and all titles derived from or based upon either class of liens shall maintain the same status between themselves so long as they remain the property of the state or any such municipality, respectively.