Year	years
1960	43.15036006316914
1961	43.753402650085214
1962	44.55102457354113
1963	45.234994148689836
1964	45.832277791473885
1965	46.3940850359602
1966	47.102062040047194
1967	47.20453996272945
1968	48.063035479286974
1969	48.62853433167091
1970	49.50418379497046
1971	48.250651522783265
1972	50.53597196569791
1973	50.992724555366635
1974	51.32255437392873
1975	51.813249322391556
1976	52.30454123698235
1977	52.67734101041228
1978	53.04048878258976
1979	53.382688088680176
1980	53.87836711740482
1981	54.40768243469677
1982	54.63427681951254
1983	54.98050003582739
1984	55.18650291386995
1985	55.19310585782834
1986	55.16752956588283
1987	55.07861834245852
1988	55.199109186860426
1989	55.318134616053065
1990	55.39103925269608
1991	55.241258265488916
1992	55.05015015342002
1993	54.852897984702466
1994	54.7125595329736
1995	54.46808808680942
1996	54.611071586231276
1997	54.6653771841519
1998	54.91702912511068
1999	55.34471392725081
2000	55.76465717273833
2001	56.009226868429494
2002	56.35843155175531
2003	56.67468543772667
2004	56.9971444858111
2005	57.033413710817804
2006	57.83625848401016
2007	58.08495115379451
2008	58.376198231335216
2009	58.71170036692731
2010	59.059051636771535
2011	59.44509488118619
2012	59.639842602036396
2013	59.95026817761183
2014	60.12149823683007
2015	60.35748183796584
2016	60.56408024403011
2017	60.879519339165455
2018	61.08247417530454
2019	61.33856404838313
2020	61.01164076878519
2021	60.67959253823564
2022	61.28382244405371