Year	years
1960	41.422545776448096
1961	41.739739358075624
1962	42.20072057552484
1963	42.44062026128874
1964	42.890837726942316
1965	43.02945129131193
1966	42.98409005214109
1967	43.232178331786336
1968	43.67073477598761
1969	43.91130716747807
1970	44.369830237344054
1971	44.870803968841535
1972	44.987343657165084
1973	45.708795356985526
1974	45.920461663804296
1975	46.30643270408786
1976	46.984952204866225
1977	47.44780321148152
1978	47.74858696016245
1979	48.210028914599825
1980	48.57245575503308
1981	48.93781946044994
1982	49.176041684886975
1983	48.332148192393504
1984	48.361807745153854
1985	48.612747526800185
1986	49.007069873759136
1987	49.33812158198551
1988	49.0201976754575
1989	49.88486949339314
1990	49.824307633487955
1991	49.69963102760737
1992	49.472160671427496
1993	49.69693251878119
1994	50.00215988334251
1995	50.11417407159537
1996	50.04852833309941
1997	50.21533670966416
1998	49.92778687430248
1999	50.64083818417793
2000	51.26454480280285
2001	51.53632182500615
2002	51.89134243641399
2003	52.36952152080999
2004	52.84880711910819
2005	53.462195048548054
2006	54.21330106958285
2007	54.84902854487474
2008	55.45071260524642
2009	56.2196130711593
2010	56.847365689080384
2011	57.55861068509845
2012	58.14101324867884
2013	58.668043004745975
2014	59.14265820191268
2015	59.56298170005856
2016	60.069024673119515
2017	60.47713845714953
2018	60.86302753889212
2019	61.24429051892341
2020	60.848894424466394
2021	60.24174346318637
2022	60.764399977527766