Year	years
1960	39.215905859381934
1961	39.51056825200568
1962	40.19694971302648
1963	40.261733760427504
1964	40.71293048974875
1965	40.847468839534876
1966	40.83508533054161
1967	41.44075740039015
1968	41.7760668812413
1969	42.008791692699226
1970	42.32401344419076
1971	42.632371667929334
1972	42.45705167153238
1973	43.237892043986506
1974	43.29799735378785
1975	43.65769711804547
1976	44.26760730474228
1977	44.61489329389345
1978	44.710046642578035
1979	45.09068740136309
1980	45.51376569308303
1981	45.79398093362241
1982	45.968342550525506
1983	44.74792475153483
1984	44.4597792276461
1985	44.86360840184736
1986	45.69146742262137
1987	46.288661145944715
1988	46.120814739579394
1989	47.3325368385343
1990	47.31779243018938
1991	47.44972973721202
1992	47.42427770966703
1993	48.08218232035144
1994	48.599660516253806
1995	49.032445642048145
1996	49.15658679622819
1997	49.5199681562106
1998	49.1815066904487
1999	50.136285604820195
2000	51.24752264449682
2001	51.746573623149175
2002	52.25005344977925
2003	52.854181087391126
2004	53.36124707371721
2005	53.97556192309539
2006	54.79572076632282
2007	55.38675544796511
2008	55.95776266007227
2009	56.62176736523508
2010	56.94484089264603
2011	57.7435386476923
2012	58.27738236041275
2013	58.73717093811637
2014	59.21261518796843
2015	59.62328113314484
2016	60.11564775988966
2017	60.49418340428595
2018	60.81934543287761
2019	61.17150857600596
2020	60.550692391299634
2021	60.016120887180875
2022	60.562845263368835