For "Enter any federal deductions attributable to the period of your New York State non-residency" what does it mean under New York Source Portion of IRA deduction?

For the entire tax year I lived in NJ and worked in NY, so I am filing NY non-resident return. My non-earning spouse contributed $6K to her traditional IRA. What amount I should add to the “New York Source Portion”? Zero, or $6K?