Any individual sixty-five years of age or older or who, for federal income tax purposes, is blind may claim an exemption in an amount specified in Subsections A through C of this section not to exceed eight thousand dollars ($8,000) of income includable except for this exemption in net income. Individuals having income both within and without this state shall apportion this exemption in accordance with regulations of the secretary:

A. for married individuals filing separate returns, for any taxable year beginning on or after January 1, 1987:

If adjusted gross income is:

The maximum amount of exemption allowable under this section shall be:

Not over $15,000                                                                     $8,000 Over $15,000 but not over $16,500                                         $7,000 Over $16,500 but not over $18,000                                         $6,000 Over $18,000 but not over $19,500                                         $5,000 Over $19,500 but not over $21,000                                         $4,000 Over $21,000 but not over $22,500                                         $3,000 Over $22,500 but not over $24,000                                         $2,000 Over $24,000 but not over $25,500                                         $1,000 Over $25,500                                                                                0.

B. for heads of household, surviving spouses and married individuals filing joint returns, for any taxable year beginning on or after January 1, 1987:

If adjusted gross income is:

The maximum amount of exemption allowable under this section shall be:

Not over $30,000                                                                     $8,000 Over $30,000 but not over $33,000                                         $7,000 Over $33,000 but not over $36,000                                         $6,000 Over $36,000 but not over $39,000                                         $5,000 Over $39,000 but not over $42,000                                         $4,000 Over $42,000 but not over $45,000                                         $3,000 Over $45,000 but not over $48,000                                         $2,000 Over $48,000 but not over $51,000                                         $1,000 Over $51,000                                                                                0.

C. for single individuals, for any taxable year beginning on or after January 1, 1987:

If adjusted gross income is:

The maximum amount of exemption allowable under this section shall be:

Not over $18,000                                                                     $8,000 Over $18,000 but not over $19,500                                         $7,000 Over $19,500 but not over $21,000                                         $6,000 Over $21,000 but not over $22,500                                         $5,000 Over $22,500 but not over $24,000                                         $4,000 Over $24,000 but not over $25,500                                         $3,000 Over $25,500 but not over $27,000                                         $2,000 Over $27,000 but not over $28,500                                         $1,000 Over $28,500                                                                                0.