Year	current US$
1997	57000000
1998	57000000
1999	57000000
2000	58000000
2001	58000000
2002	62000000
2003	66000000
2004	31000000
2005	30000000
2006	29000000
2007	47000000
2008	46000000
2009	47000000
2010	62000000
2011	112000000
2012	138000000
2013	147000000
2014	156000000
2015	166000000
2016	176000000
2017	187000000
2018	199000000
2019	213000000
2020	240000000