Year	current US$
1998	16000000
1999	11000000
2000	7000000
2001	13000000
2002	7000000
2003	9000000
2004	8000000
2005	9000000
2006	3000000
2007	11000000
2008	10000000
2009	8000000
2010	6000000
2011	8000000
2012	4000000
2013	5000000
2014	7000000
2015	10000000
2016	14000000
2017	21000000
2018	20000000
2019	24000000
2020	9000000