"Residence" for the purpose of registering and voting means a person's permanent address where he or she physically resides and maintains his or her abode. However, no person gains residence by reason of his or her presence or loses his or her residence by reason of his or her absence:
(1) While employed in the civil or military service of the state or of the United States;
(2) While engaged in the navigation of the waters of this state or the United States or the high seas;
(3) While a student at any institution of learning;
(4) While confined in any public prison.
Absence from the state on business shall not affect the question of residence of any person unless the right to vote has been claimed or exercised elsewhere.