As used in this article, the term:

(1) "Contiguous area" means any unincorporated area which, on or after January 1, 1999, had an aggregate external boundary directly abutting a municipal boundary. Any area shall be considered "contiguous" if the aggregate external boundary would directly abut the municipal boundary if not otherwise separated, in whole or in part, from the municipal boundary by lands owned by the municipal corporation, by lands owned by a county, or by lands owned by this state or by the definite width of:

(A) Any street or street right of way;

(B) Any creek or river; or

(C) Any right of way of a railroad or other public service corporation.

(2) "Municipal corporation" means a municipal corporation which has a population of 200 or more persons according to the United States decennial census of 1980 or any future such census.

(3) "Unincorporated island" means:

(A) An unincorporated area in existence on January 1, 1991, with its aggregate external boundaries abutting the annexing municipality;

(B) An unincorporated area in existence as of January 1, 1991, with its aggregate external boundaries abutting any combination of the annexing municipality and one or more other municipalities; or

(C) An unincorporated area in existence as of January 1, 1991, which the county governing authority has by resolution adopted not later than 90 days following July 1, 1992, that identifies any unincorporated area of the county to which the county has no reasonable means of physical access for the provision of services otherwise provided by the county governing authority solely to the unincorporated area of the county.