Table of Contents 2018 Compared with 2017 2017 Compared with 2016 29 Core income decreased $74 million in 2018 as compared with 2017. Excluding the favorable effect of the Federal corporate income tax rate change, core income for our Property & Casualty Operations decreased approximately $158 million primarily due to lower net investment income driven by limited partnership returns and lower favorable net prior year loss reserve development partially offset by lower net catastrophe losses. Excluding the unfavorable effect of the Federal corporate income tax rate change which reduced the income tax benefit, core income for our Life & Group segment increased approximately $42 million while core loss for our Corporate & Other segment increased approximately $46 million. Pretax net catastrophe losses were $252 million in 2018 as compared with $380 million in 2017. Favorable net prior year loss reserve development of $181 million and $308 million was recorded in 2018 and 2017 related to our Specialty, Commercial, International and Corporate & Other segments. Further information on net prior year loss reserve development is in Note E to the Consolidated Financial Statements included under Item 8. Core income increased $95 million in 2017 as compared with 2016. Core income for our Property & Casualty Operations declined $23 million primarily driven by higher net catastrophe losses partially offset by improved non-catastrophe current accident year underwriting results. Core loss for our operations outside of Property & Casualty Operations improved $118 million driven by lower adverse prior year A&EP reserve development. Pretax net catastrophe losses were $380 million in 2017 as compared with $165 million in 2016. Favorable net prior year loss reserve development of $308 million and $288 million was recorded in 2017 and 2016 related to our Specialty, Commercial, International and Corporate & Other segments. Further information on net prior year loss reserve development is in Note E to the Consolidated Financial Statements included under Item 8.