Year	current US$
1962	250
1963	260
1964	280
1965	320
1966	340
1967	350
1968	360
1969	360
1970	380
1971	410
1972	460
1973	600
1974	780
1975	900
1976	960
1977	1020
1978	1180
1979	1510
1980	1870
1981	2010
1982	1930
1983	1870
1984	2020
1985	1980
1986	1920
1987	2020
1988	2210
1989	2330
1990	2470
1991	2630
1992	2950
1993	3310
1994	3670
1995	4120
1996	4570
1997	4690
1998	3690
1999	3430
2000	3490
2001	3570
2002	3800
2003	4160
2004	4710
2005	5230
2006	5770
2007	6540
2008	7400
2009	7470
2010	8110
2011	8890
2012	9980
2013	10600
2014	10870
2015	10400
2016	9880
2017	9680
2018	10360
2019	10960
2020	10320
2021	10740
2022	11830
2023	11970