Except as otherwise provided by law, the assessing official shall, from information entered on the tax return list and from all other information known to him or her, or which he or she may procure, proceed to ascertain what, in his or her best judgment, is a fair and reasonable market value of each item of property returned by or listed to any taxpayer; provided, that the assessed value of any real estate or improvements as fixed for taxation for the year next preceding the then current tax year shall be prima facie the basis of the value of the property for assessment for the current tax year, and the property shall not be assessed for taxation at a less valuation unless, upon evidence submitted to the county board of equalization, as provided for herein, it is found that the assessed valuation of the property reviewed should be reduced. The assessing official shall in separate columns enter on the list the amount and value and the deduction for exemption to which the taxpayer is entitled. The assessing official shall also add to the list any item of property subject to taxation owned by the taxpayer, or in which he or she has any interest whatever and which he or she had failed or omitted to place on the list; and the taxpayer shall be given notice by the assessing official, by mail or in person, of the items of property added to his or her assessment list or items claimed as exempt which are disallowed by the assessing official after the list has been filed and before the assessing official has completed his or her assessment, and the assessing official shall, upon demand, furnish the taxpayer with a certified copy of his or her assessment list so amended. In the event the value of real or personal property of any taxpayer is increased by the county board of equalization, herein created, over the assessed value thereof for the next preceding year, the taxpayer shall be furnished by mail or in person, by the secretary of the county board of equalization, with a statement showing separately the value of his or her personal property and his or her real property, and improvements thereon. The statement shall be signed by the chair of the county board of equalization and the taxpayer may file in writing, with the secretary of the county board of equalization, within 30 calendar days of the date of the statement, objections to any assessed valuation fixed as herein provided. Failure to give or receive the notices required in this section shall not invalidate the assessment. The taxpayer shall have the right any time before the taxes become delinquent to appear before the county board of equalization and have the assessment of his or her property reopened, if satisfactory proof is made that the taxpayer or his or her agent did not receive notice of the increase. The expense of postage incurred in carrying out the provisions of this section shall be paid in equal proportions by the county and state, upon a certified statement thereof by the secretary of the county board of equalization, filed with the court of county commissioners, or the board or court of like jurisdiction and with the Department of Finance.