Notwithstanding any provision of the statutes of this State to the contrary, no individual, corporation or other taxpayer, and no item of income, shall be exempt from taxation under this chapter unless the individual, corporation, other taxpayer or item of income, as the case may be, is expressly exempted from taxation by this chapter. (Added 1966, No. 61 (Sp. Sess.), § 1, eff. Jan. 1, 1966; amended 1967, No. 121, § 2, eff. Jan. 1, 1968 for taxable years beginning on or after Jan. 1, 1968.)