The following definitions apply to terms found in this sub-chapter:

(1) "Net capital gain" means an individual's net capital gain included in Montana adjusted gross income as shown on their Montana individual income tax return.

(2) "Tax year 2005" means the taxpayer's tax year beginning after December 31, 2004.

(3) "Tax year 2006" means the taxpayer's tax year beginning after December 31, 2005.