Year	constant 2015 US$
1991	4418.382240038964
1992	4689.727790992077
1993	4871.034393895357
1994	4946.927569145399
1995	4986.866509740385
1996	5126.513731622921
1997	5493.4993549859655
1998	5800.958179825884
1999	6207.929043816966
2000	6579.305506381899
2001	7170.049805080995
2002	7623.243516768812
2003	8096.466071810998
2004	8451.03233569451
2005	9170.86291478184
2006	10132.558298529493
2007	11652.185771685203
2008	12588.837254481214
2009	13463.498046849953
2010	14551.88389739246
2011	15360.114500739695
2012	16399.669342254554
2013	16654.83680279305
2014	17094.101430811064
2015	17793.526317737043
2016	19004.465877474882
2017	20447.11995991457
2018	21876.002088141446
2019	23231.982105886244
2020	23857.112322467423
2021	25235.82777708243
2022	25588.44417532124