Year	constant 2015 US$
1991	3990.415004373885
1992	3967.7570470355363
1993	3822.839004346832
1994	3793.0084156124394
1995	3812.871654087856
1996	3656.552190287492
1997	3732.4947416353516
1998	3825.753928035866
1999	3779.606328802753
2000	3724.556372203552
2001	3699.7732675624397
2002	3635.9086305874584
2003	3645.979447116534
2004	3690.494006515199
2005	3734.7979509691004
2006	3790.5035192168893
2007	3963.8073138404297
2008	4246.588017350313
2009	4281.537471157822
2010	4155.795713568419
2011	4174.712027219622
2012	4268.201836236377
2013	4409.652193784526
2014	4427.693714907662
2015	4365.033809696196
2016	4355.803957478289
2017	4290.79310419385
2018	4273.957385911223
2019	4300.50753209597
2020	4253.72365772176
2021	4271.413136640215
2022	4293.3368551715175