Year	current US$
1988	2000000
1989	2000000
1990	3000000
1991	11000000
1992	9000000
1993	8000000
1994	22000000
1995	23000000
1996	19000000
1997	16000000
1998	6000000
1999	8000000
2000	9000000
2001	13000000
2002	14000000
2003	15000000
2004	20000000
2005	25000000
2006	18000000
2007	18000000
2008	20000000
2009	21000000
2010	32000000
2011	50000000
2012	107000000
2013	65000000
2014	55000000
2015	52000000
2016	36000000
2017	40000000
2018	41000000
2019	55000000
2020	44000000
2021	90000000
2022	96000000
2023	59000000