Year	constant 2010 US$
1991	4224.52906767824
1992	3922.14476910831
1993	3935.716357177
1994	3581.29746718578
1995	3570.89997583725
1996	3595.19931051632
1997	3816.9076331404
1998	3674.15231536195
1999	3508.88772002888
2000	3760.748179372
2001	4127.85000123819
2002	4522.92375422754
2003	4550.43152397295
2004	5042.59144651553
2005	5141.64522503846
2006	5361.20411929655
2007	5292.68590081964
2008	5634.94433367132
2009	5907.63313843129
2010	5691.01947967895
2011	6165.9189447188
2012	6076.55597379185
2013	6510.5136311193
2014	7050.13288508034
2015	7362.18454400833
2016	7610.22586918384
2017	8071.67286032313
2018	8191.78383421806