Year	current US$
1997	26000000
1998	24000000
1999	43000000
2000	44000000
2001	44000000
2002	47000000
2003	49000000
2004	55000000
2005	57000000
2006	63000000
2007	73000000
2008	118000000
2009	96000000
2010	105000000
2011	111000000
2012	165000000
2013	210000000
2014	222000000
2015	234000000
2016	247000000
2017	223000000
2018	279000000
2019	298000000
2020	234000000