Year	current US$
1988	68000000
1989	73000000
1990	84000000
1991	89000000
1992	99000000
1993	109000000
1994	98000000
1995	89000000
1996	100000000
1997	99000000
1998	100000000
1999	97000000
2000	107000000
2001	114000000
2002	104000000
2003	118000000
2004	133000000
2005	130000000
2006	137000000
2007	142000000
2008	155000000
2009	172000000
2010	168000000
2011	188000000
2012	194000000
2013	188000000
2014	161000000
2015	160000000
2016	186000000
2017	183000000
2018	198000000
2019	215000000
2020	213000000
2021	254000000
2022	277000000
2023	301000000