Note 13 - Segment Information - Continued Unum US Unum International Colonial Life Closed Block Corporate Total (in millions of dollars) Year Ended December 31, 2020 Premium Income $ 6,018.9  $ 652.8  $ 1,712.0  $ 994.4  $ —  $ 9,378.1  Net Investment Income 720.3  104.6  155.7  1,370.3  9.8  2,360.7  Other Income 154.9  0.5  1.1  66.6  1.1  224.2  Adjusted Operating Revenue $ 6,894.1  $ 757.9  $ 1,868.8  $ 2,431.3  $ 10.9  $ 11,963.0  Adjusted Operating Income (Loss) $ 825.4  $ 76.6  $ 335.4  $ 241.4  $ (200.8) $ 1,278.0  Interest and Debt Expense $ —  $ —  $ —  $ 3.1  $ 185.1  $ 188.2  Depreciation and Amortization $ 421.7  $ 20.1  $ 273.9  $ 5.9  $ 0.7  $ 722.3  Year Ended December 31, 2019 Premium Income $ 6,016.6  $ 630.5  $ 1,685.0  $ 1,033.5  $ —  $ 9,365.6  Net Investment Income 739.4  122.5  148.0  1,404.9  20.5  2,435.3  Other Income 142.8  0.6  3.4  71.3  3.1  221.2  Adjusted Operating Revenue $ 6,898.8  $ 753.6  $ 1,836.4  $ 2,509.7  $ 23.6  $ 12,022.1  Adjusted Operating Income (Loss) $ 1,031.1  $ 107.9  $ 344.5  $ 137.7  $ (188.6) $ 1,432.6  Interest and Debt Expense $ —  $ —  $ —  $ 5.3  $ 172.1  $ 177.4  Depreciation and Amortization $ 422.8  $ 18.7  $ 276.6  $ 7.7  $ 1.7  $ 727.5  Year Ended December 31, 2018 Premium Income $ 5,736.4  $ 568.8  $ 1,603.8  $ 1,077.1  $ —  $ 8,986.1  Net Investment Income 778.7  117.2  151.2  1,377.1  29.5  2,453.7  Other Income 118.5  0.4  1.2  75.4  2.7  198.2  Adjusted Operating Revenue $ 6,633.6  $ 686.4  $ 1,756.2  $ 2,529.6  $ 32.2  $ 11,638.0  Adjusted Operating Income (Loss) $ 1,014.6  $ 113.9  $ 335.2  $ 125.5  $ (171.1) $ 1,418.1  Interest and Debt Expense $ —  $ —  $ —  $ 6.9  $ 160.4  $ 167.3  Depreciation and Amortization $ 389.6  $ 17.6  $ 257.3  $ 8.3  $ 1.0  $ 673.8  200 NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued Unum Group and Subsidiaries