Year	constant 2015 US$
1995	3968.543327600557
1996	4176.44686731652
1997	4116.307385429086
1998	4024.7929950114776
1999	3879.4048173579777
2000	3555.075566184537
2001	3513.0402331074893
2002	3542.66564289257
2003	3361.5454366469753
2004	3540.2133686337543
2005	3614.9029445722203
2006	3894.3017800863668
2007	4259.630247525201
2008	4531.003128947396
2009	4449.980478680841
2010	4888.236784480844
2011	5084.72249331108
2012	4978.569510686737
2013	5325.695066386394
2014	5547.742739473071
2015	5631.4864429165955
2016	5802.014269462247
2017	6008.439058334918
2018	6117.929614920978
2019	6038.002266267746
2020	5884.430927691294
2021	6033.241336327579
2022	5994.6075038233985
2023	6205.767601963883