A Treasurer, Auditor of Public Accounts, Commissioner of Agriculture, Labor and Statistics, Secretary of State, and Attorney-General, shall be elected by the qualified voters of the State at the same time the Governor and Lieutenant Governor are elected, for the term of four years, each of whom shall be at least thirty years of age at the time of his election, and shall have been a resident citizen of the State at least two years next before his election. The duties of all these officers shall be such as may be prescribed by law, and the Secretary of State shall keep a fair register of and attest all the official acts of the Governor, and shall, when required, lay the same and all papers, minutes and vouchers relative thereto before either House of the General Assembly. The officers named in this section shall enter upon the discharge of their duties the first Monday in January after their election, and shall hold their offices until their successors are elected and qualified.