The following table shows gross premiums written allocated between excess of loss, proportional and delegated authority for each of our segments: Year ended December 31, 2021 Property Casualty and Specialty Total (in thousands) Excess of loss $ 2,485,999 $ 663,749 $ 3,149,748 Proportional 924,342 2,853,339 3,777,681 Delegated authority 548,383 357,986 906,369 Total gross premiums written $ 3,958,724 $ 3,875,074 $ 7,833,798 Year ended December 31, 2020 (in thousands) Excess of loss $ 2,075,961 $ 626,468 $ 2,702,429 Proportional 656,653 1,925,884 2,582,537 Delegated authority 266,528 254,671 521,199 Total gross premiums written $ 2,999,142 $ 2,807,023 $ 5,806,165 Year ended December 31, 2019 (in thousands) Excess of loss $ 1,758,787 $ 508,515 $ 2,267,302 Proportional 546,405 1,583,554 2,129,959 Delegated authority 125,793 284,696 410,489 Total gross premiums written $ 2,430,985 $ 2,376,765 $ 4,807,750 Property Segment Our Property segment includes our catastrophe class of business, principally comprised of excess of loss reinsurance and excess of loss retrocessional reinsurance to insure insurance and reinsurance companies against natural and man-made catastrophes. It also includes our other property class of business, primarily comprised of proportional reinsurance, property per risk, property (re)insurance, binding facilities and regional U.S. multi-line reinsurance, certain of which have exposure to natural and man-made catastrophes. The following table shows gross premiums written in our Property segment allocated by class of business: Year ended December 31, 2021 2020 2019 (in thousands, except percentages) Gross Premiums Written Percentage of Gross Premiums Written Gross Premiums Written Percentage of Gross Premiums Written Gross Premiums Written Percentage of Gross Premiums Written Catastrophe $ 2,235,736 56.5 % $ 1,886,785 62.9 % $ 1,595,472 65.6 % Other property 1,722,988 43.5 % 1,112,357 37.1 % 835,513 34.4 % Total Property segment gross premiums written $ 3,958,724 100.0 % $ 2,999,142 100.0 % $ 2,430,985 100.0 % We write catastrophe reinsurance and insurance coverage protecting against large natural catastrophes, such as earthquakes, hurricanes, typhoons and tsunamis, as well as claims arising from other natural and man-made catastrophes such as winter storms, freezes, floods, fires, windstorms, tornadoes, explosions and acts of terrorism. We offer this coverage to insurance companies and other reinsurers primarily on an excess of loss basis. This means we begin paying when our customers’ claims from a catastrophe exceed a certain retained amount. We also offer proportional coverages and other structures on a catastrophe- exposed basis and may increase these offerings on an absolute or relative basis in the future. Recently, as our other property class of business has become a larger percentage of our Property segment gross premiums written, proportional coverage and business written through delegated authority arrangements have become larger percentages of our Property segment. 6