Year	constant 2015 US$
1998	4509.017738046938
1999	4415.002210131148
2000	4409.92699931208
2001	4594.59727085573
2002	4567.215342498563
2003	5139.262821593088
2004	5374.313009021229
2005	5422.235716760914
2006	5589.7442255557335
2007	6552.748573049691
2008	6803.063085685924
2009	7518.111315129036
2010	7454.730623330047
2011	7174.027976221281
2012	7218.32772462946
2013	6892.875200455534
2014	6826.761481478805
2015	6771.820771609938
2016	6782.460867071809
2017	7178.422497537358
2018	7152.607817047383
2019	6877.709974192537
2020	7632.491111308118
2021	8190.013529830232