Year	current US$
1998	12000000
1999	9000000
2000	13000000
2001	12000000
2002	18000000
2003	19000000
2004	18000000
2005	19000000
2006	17000000
2007	23000000
2008	19000000
2009	24000000
2010	25000000
2011	26000000
2012	27000000
2013	27000000
2014	27000000
2015	26000000
2016	32000000
2017	24000000
2018	30000000
2019	17000000
2020	5000000