Year	current US$
1990	977.0743336975348
1991	1311.334236966793
1992	1526.956160250106
1993	1756.538835956796
1994	2282.401479244228
1995	3089.875429546103
1996	3508.289669113852
1997	3499.555848614891
1998	3847.9342650169547
1999	3746.8954268360667
2000	3847.90105765596
2001	4251.626773389752
2002	4438.6137647209425
2003	4815.263553982913
2004	5524.96424876965
2005	6747.053336449084
2006	7543.108522920254
2007	9386.707870953025
2008	11941.317446388806
2009	9791.852122346498
2010	10519.151772035804
2011	11566.237159988472
2012	11004.725188486827
2013	11445.939399933664
2014	11957.20904035517
2015	10613.080624815078
2016	10405.661261775935
2017	11609.618130566654
2018	13050.242229783686
2019	13241.256602109495
2020	13333.543284684585
2021	15098.239663879345