Year	current US$
1996	1000000
1997	7000000
1998	21000000
1999	16000000
2000	12000000
2001	9000000
2002	17000000
2003	18000000
2004	23000000
2005	36000000
2006	50000000
2007	103000000
2008	146000000
2009	126000000
2010	127000000
2011	145000000
2012	179000000
2013	155000000
2014	178000000
2015	136000000
2016	121000000
2017	130000000
2018	137000000
2019	128000000
2020	96000000