Year	current US$
1960	1.4173496868338427
1961	1.7258459293568689
1962	1.7279349497596375
1963	1.8265241474891996
1964	1.7671971056252191
1965	1.8711915253105147
1966	1.8807890090683046
1967	1.871750466257141
1968	1.656924346437626
1969	1.6454633838948427
1970	1.7749032521441503
1971	1.9814458727310265
1972	2.061017656495325
1973	2.696688450569053
1974	3.58058949988172
1975	4.507589452044313
1976	4.274308514554825
1977	4.391639218018285
1978	5.79170339382668
1979	6.458376789353175
1980	7.635321884261413
1981	7.209311932494981
1982	6.4405957866887364
1983	6.071717676986016
1984	6.175548817815875
1985	6.476109195047987
1986	7.475402942518508
1987	8.106931874656771
1988	8.540245826276815
1989	8.665824833101693
1990	10.774787379214294
1991	11.235400968818222
1992	10.890005714939266
1993	9.868137348941659
1994	10.421163402888666
1995	10.053483569362967
1996	9.41788443234143
1997	8.074604747468761
1998	8.408799931924525
1999	8.53721252071754
2000	7.924163049411149
2001	8.177856817081958
2002	9.628751161786129
2003	10.990309292148888
2004	12.158778665369896
2005	16.350194342921046
2006	15.913868044732435
2007	14.661304478597295
2008	17.41381204356792
2009	16.59477146259031
2010	18.43086148576062
2011	19.739042594126484
2012	18.68785357963778
2013	20.88071340078839
2014	22.074035049240553
2015	19.792227824869403
2016	21.16525096847926
2017	21.73949072686965
2018	21.811493959353978
2019	21.02157241919639
2020	24.673195028209225
2021	25.65436327788174
2022	30.62499400929972