Year	current US$
1996	3934159169.7620807
1997	4065336508.2784595
1998	4350963515.384012
1999	4484057424.373511
2000	4789169471.646981
2001	4651436245.201132
2002	5012992609.242892
2003	5557633181.152137
2004	6257871071.022305
2005	7415626035.103832
2006	9192136613.674114
2007	10684012277.016968
2008	12203341684.87617
2009	11594825930.108131
2010	12987466225.565687
2011	13285557119.657152
2012	13831452815.30139
2013	14412795538.921011
2014	14564480207.635956
2015	15411965687.683805
2016	14254780934.8461
2017	14941721782.903864
2018	16440068107.596142
2019	17082193037.970308