Year	Percent
1980	1.253
1981	1.225
1982	1.206
1983	1.197
1984	1.182
1985	1.172
1986	1.167
1987	1.144
1988	1.145
1989	1.154
1990	1.155
1991	1.156
1992	1.055
1993	1.048
1994	1.048
1995	1.039
1996	1.036
1997	1.038
1998	1.058
1999	1.074
2000	1.068
2001	1.067
2002	1.039
2003	1
2004	0.969
2005	0.944
2006	0.927
2007	0.913
2008	0.906
2009	0.876
2010	0.843
2011	0.823
2012	0.789
2013	0.763
2014	0.747
2015	0.737
2016	0.73
2017	0.724
2018	0.717
2019	0.707
2020	0.694
2021	0.68
2022	0.667
2023	0.653
2024	0.64