Year	current US$
1960	11000000
1961	11000000
1962	6000000
1963	6000000
1964	4000000
1965	5000000
1966	3000000
1967	4000000
1968	4000000
1969	4000000
1970	3000000
1971	4000000
1972	4000000
1973	8000000
1974	13000000
1975	11000000
1976	8000000
1977	11000000
1978	7000000
1979	14000000
1980	23000000
1981	47000000
1982	39000000
1983	27000000
1984	16000000
1985	13000000
1986	8000000
1987	48000000
1988	447000000
1989	606000000
1990	692000000
1991	659000000
1992	619000000
1993	611000000
1994	934000000
1995	1945000000
1996	2675000000
1997	2504000000
1998	1496000000
1999	2440000000
2000	4079000000
2001	3374000000
2002	3336000000
2003	3733000000
2004	4072000000
2005	5608000000
2006	6654000000
2007	6299000000
2008	7584000000
2009	6259000000
2010	6437000000
2011	6948000000
2012	7062000000
2013	7130000000
2014	2417000000
2015	510000000
2016	411000000
2017	418000000
2018	570000000
2019	652000000
2020	404000000
2021	662000000
2022	690000000
2023	226000000