If a partnership qualifies as an export taxpayer, its partners may exclude from gross income for Colorado income tax purposes such partners' distributive share of any such partnership income or gain which constitutes foreign source income for federal income tax purposes. For the purposes of this section, an 'export taxpayer' means any partnership which is subject to the provisions of this article and which sells fifty percent or more of its product or products which are produced in Colorado in states other than Colorado or in foreign countries or, if the gross receipts of such partnership are derived from the performance of services, such services are performed in Colorado by a partner or employee of the partnership and fifty percent or more of such services provided by the partnership are sold or provided to persons outside of Colorado.L. 93: Entire section added, p. 1320, § 3, effective June 6. L. 95: Entire section amended, p. 818, § 45, effective May 24.