The person giving in property for taxation shall enter upon said list his estimated value of every item of personal property listed, for the information of the official or officials whose duty it is to fix the assessment valuation of taxable property, but nothing in this title shall be construed as requiring the taxpayer to make oath as to the value of the property. It shall be the duty of the tax assessor to enter upon the tax return in the column provided the next preceding year‘s valuation for assessment of real estate and improvements and also to note on the tax return list whether there has been any physical change, such as in improvements, etc., since the preceding year’s assessment was made. Every person shall enter upon the assessment list his occupation and post-office address.