Year	constant 2015 US$
1996	52171.347479524484
1997	53720.39084483961
1998	54225.04395030844
1999	54782.03580865981
2000	55773.24850964895
2001	56188.552631782084
2002	56294.99205790025
2003	56563.1066243422
2004	56994.3383696379
2005	57468.438873411375
2006	58052.589643711515
2007	58707.19879483387
2008	58495.23820028247
2009	57119.64569770292
2010	57705.2410028404
2011	58397.824829995516
2012	58729.6266091512
2013	59093.675890405444
2014	59304.19321110151
2015	74472.31802656387
2016	59671.889293307075
2017	60304.47961877503
2018	60458.130752474666
2019	60666.023255721455
2020	58302.284114690745
2021	60612.08211256627
2022	61345.68499765999