Year	%
1963	1.8
1964	1.8
1965	1.9
1966	1.8
1967	1.9
1968	2
1969	2.1
1970	2
1971	2
1972	1.9
1973	2
1974	2
1975	2
1976	2.1
1977	2.1
1978	2.1
1979	2.2
1980	2.3
1981	2.2
1982	2
1983	1.9
1984	1.9
1985	1.9
1986	1.9
1987	1.9
1988	2
1989	2
1990	2
1991	2
1992	1.9
1993	1.8
1994	1.9
1995	1.9
1996	1.9
1997	1.9
1998	1.9
1999	1.9
2000	1.9
2001	1.9
2002	1.8
2003	1.7
2004	1.8
2005	1.8
2006	1.7
2007	1.7
2008	1.7
2009	1.8
2010	1.8
2011	1.8
2012	1.8
2013	1.8
2014	1.7
2015	1.8
2016	1.8
2017	1.7
2018	1.7
2019	1.8
2020	2
2021	2.2