Year	years
1960	36.449395919628905
1961	36.76407254219356
1962	37.56640245342807
1963	37.87866005666239
1964	38.10102266393706
1965	38.427363316756484
1966	38.67589917708798
1967	38.014845715364984
1968	38.664320803494284
1969	38.969390266644275
1970	39.89009419116686
1971	40.46609095086741
1972	41.16319097696989
1973	41.815577815131256
1974	42.451510845140355
1975	43.11312362005278
1976	43.8516011602725
1977	44.50695004325484
1978	44.988173831878754
1979	45.3865610916076
1980	45.70329054057968
1981	46.03038897616168
1982	46.24279308344382
1983	46.498480944674114
1984	46.64511259970675
1985	46.688084711637
1986	46.757499803685114
1987	46.80572347822744
1988	47.115535683379136
1989	47.279733441752136
1990	47.152056124936884
1991	47.21755798208769
1992	47.276526062265084
1993	47.39136492587189
1994	47.284382883718095
1995	47.38697296631699
1996	47.51506214675134
1997	47.70111057494718
1998	48.10186387570734
1999	48.524148583851265
2000	49.07771249905159
2001	49.46567698791821
2002	49.8332997902483
2003	50.29497067379433
2004	50.757006716806224
2005	51.296532149264806
2006	51.834634242423455
2007	52.25778250083005
2008	52.741954744970734
2009	53.24110075498884
2010	53.65788417724439
2011	54.10131434381043
2012	54.42209012481785
2013	54.73281544312579
2014	54.9676741841976
2015	55.233506947308754
2016	55.71710556120907
2017	55.94266378321405
2018	56.271812470012826
2019	56.57739212259525
2020	56.131022627744386
2021	55.90341913181697
2022	56.556727337476126