Year	current US$
1960	1.47795189788003
1961	1.853218431424106
1962	1.7799464495992303
1963	1.8925825349699523
1964	1.954420650183793
1965	2.0440636472587608
1966	2.0718044643621494
1967	2.061734009108496
1968	1.8172859875097023
1969	1.747268616876605
1970	1.8288741097578096
1971	1.9591540543459842
1972	1.9139664824282716
1973	2.440901050518445
1974	3.2437333494759866
1975	4.199977844040181
1976	4.00030077179545
1977	3.8829616578353923
1978	4.645412972573689
1979	5.122962178766692
1980	6.275754164493761
1981	5.900140850655823
1982	5.491696646344593
1983	4.999652680201769
1984	4.988650956423553
1985	5.047217372331977
1986	5.837074320980588
1987	6.36265806095077
1988	6.82896144886749
1989	7.065318722799705
1990	9.321572633979333
1991	9.917383051702883
1992	9.457499741135695
1993	8.594351652380972
1994	9.061114636930924
1995	8.808967221356307
1996	7.8209265202776095
1997	6.6316737504088765
1998	7.10502296738812
1999	7.5079981426833635
2000	6.695658979093693
2001	6.991095057981444
2002	7.520581924748004
2003	7.825471246162973
2004	8.913848874908629
2005	14.296100488516455
2006	12.839827309837341
2007	10.44961132967302
2008	11.644674478220631
2009	10.633157639632612
2010	11.709974035241194
2011	12.354513664677192
2012	12.174394772664897
2013	13.65851497548022
2014	13.060267620368872
2015	11.996382217884634
2016	12.171571641123835
2017	12.233547636647822
2018	11.589525572409629
2019	11.178846184623445
2020	14.518649248933858
2021	14.62329419455004
2022	18.453847810694057