Year	years
1980	65.5
1981	67.7
1982	64.3
1983	65.7
1984	65.7
1985	63.6
1986	64.9
1987	63.7
1988	64.8
1989	62.8
1990	62.4
1991	65.2
1992	65.8
1993	64.2
1994	65.9
1995	65.8
1996	66
1997	65.7
1998	67.6
1999	67.4
2000	67.9
2001	67.4
2002	66.6
2003	66.2
2004	69.1
2005	67.4
2006	68.9
2007	68.9
2008	67.7
2009	68.4
2010	69.1
2011	67.7
2012	69.3
2013	69.9
2014	68.4
2015	70.1
2016	68.7
2017	70.3
2018	68.5
2019	69.9
2020	72.7
2021	71.3
2022	71.8