Year	current US$
1993	928.4112845419958
1994	967.126467547035
1995	1136.5376070153584
1996	1276.7428832996268
1997	1335.3524865869524
1998	1381.725540991071
1999	1443.2684194375042
2000	1454.5914591904202
2001	1492.0329023383395
2002	1465.6870317475355
2003	1554.5847798236791
2004	1791.706331673502
2005	2017.3037713743613
2006	2327.333821078248
2007	2855.821348090812
2008	3416.684243923919
2009	3414.5921344733893
2010	3827.3377445105775
2011	3790.024718006919
2012	4007.238805478421
2013	3616.3626338547406
2014	3526.551725632082
2015	3201.686821129081
2016	3254.171525433491
2017	3096.7955217206786
2018	2788.4514085139085
2019	2802.5205926430694
2020	2606.8486559540534
2021	2906.0454223654892