Year	constant 2015 US$
1991	17782.982322573225
1992	19609.437674528574
1993	22430.286042726682
1994	23783.671498521835
1995	25685.024276120526
1996	27890.53193306691
1997	29645.974541815245
1998	30884.98518699529
1999	34330.88426168094
2000	34953.20369212724
2001	33300.092018833035
2002	33130.67032798684
2003	32723.54155217572
2004	40604.57499123786
2005	38250.24296044637
2006	36882.054354033855
2007	39674.62557667763
2008	43026.363846257336
2009	43301.35665300098
2010	43125.604062611135
2011	45130.37095426387
2012	44256.00949632886
2013	46315.05799204958
2014	44313.10939704379
2015	44736.367747119155
2016	42615.56593177798
2017	41611.63408320955
2018	42290.67271377953
2019	40298.531416241814
2020	38385.324011668126
2021	37661.18475162414
2022	40181.04861838423