Year	constant 2015 US$
1991	9415.822846714955
1992	9053.078633427693
1993	9196.365885978903
1994	9510.846677430573
1995	9650.41385841444
1996	8060.180491068803
1997	7984.549663370694
1998	7983.334160741956
1999	7907.579136420984
2000	7544.771280328584
2001	7717.980804101751
2002	7675.991094469173
2003	8159.166924252938
2004	8829.00372642967
2005	9224.998168451408
2006	9287.915355700163
2007	10371.833577588677
2008	10519.605233257078
2009	9353.938379788473
2010	9678.47097561897
2011	9263.79607547631
2012	6999.573519496216
2013	6871.951850427965
2014	6875.628722349758
2015	6627.492996592266
2016	6634.711859332558
2017	6354.03218291611
2018	5853.738077091024
2019	5414.5235610533
2020	5297.033031866087
2021	4908.083192854354
2022	4469.354924168241