Year	years
1960	37.84515161815242
1961	38.16494977954173
1962	38.73510186094673
1963	39.06371527596247
1964	39.33536025453534
1965	39.61803769555224
1966	39.83782698849332
1967	39.47150006120723
1968	40.08567892093013
1969	40.350420384533955
1970	41.03476138350061
1971	41.55672110540693
1972	42.24979260465379
1973	42.85504710551197
1974	43.49768365068481
1975	44.201253848732016
1976	45.00316314299184
1977	45.7198894946875
1978	46.26953508837604
1979	46.673735870634154
1980	47.01523876934953
1981	47.297189967204524
1982	47.529378486772984
1983	47.78526223116568
1984	47.93192037969265
1985	48.02167572635965
1986	48.066763733548605
1987	48.237852232417204
1988	48.512913121058574
1989	48.68984741339536
1990	48.650003390501645
1991	48.66246101428379
1992	48.73726633988373
1993	48.8320388374723
1994	48.68189229487961
1995	48.783772853226864
1996	48.906277328806325
1997	49.079183766065874
1998	49.33294923700926
1999	49.75011677340632
2000	50.22195387535903
2001	50.565144130827036
2002	50.92784833353279
2003	51.4033564775689
2004	51.81913179400345
2005	52.34455122726462
2006	52.832125682220614
2007	53.25171156800027
2008	53.64116467553644
2009	54.159420838929194
2010	54.55016916510802
2011	55.01313789358718
2012	55.34056098699718
2013	55.67340551413402
2014	55.92222899084315
2015	56.19587234636735
2016	56.58167848505035
2017	56.88844583028204
2018	57.18913926806546
2019	57.555795551751196
2020	57.22637273123987
2021	56.988656782013855
2022	57.62617616419705