Year	constant 2015 US$
1991	19663.080138300556
1992	23137.533455687186
1993	22461.890043261305
1994	23995.93340354561
1995	26177.421942734847
1996	28128.9643225175
1997	29294.39961619595
1998	31405.08874842355
1999	33885.27976126459
2000	33486.599730639995
2001	32378.591774726694
2002	33347.97048656956
2003	26775.164437818174
2004	35706.84071689707
2005	36108.30327241941
2006	35164.435076748814
2007	36761.07471540555
2008	47032.49932135338
2009	47326.28249826383
2010	46170.37107726726
2011	47734.181505797416
2012	43537.68470038177
2013	40454.46449584553
2014	50378.502104102445
2015	52143.35092263014
2016	43463.07799939028
2017	51520.38157066301
2018	55374.43699453274
2019	53404.082508784726
2020	53909.37233637023
2021	47144.86136248827
2022	47973.968416586555
