As used in this chapter, the term:

(1) "Residence" shall mean the physical location of a student's principal abode—i.e., the home, house, apartment, facility, structure, etc., within which the student lives the majority of the time. The mailing address of the student—e.g., the parents' address or post office box—may be different than the student's principal abode. The lack of a mailing address does not preclude residency under this section.

(2) "Nonresident student" shall mean a student, otherwise eligible for enrollment, who is between the ages of three and twenty-one, and whose residence is located outside the state of Washington.