Year	Percent
1980	1.396
1981	1.476
1982	1.505
1983	1.529
1984	1.576
1985	1.581
1986	1.637
1987	1.679
1988	1.719
1989	1.809
1990	1.895
1991	2.016
1992	1.928
1993	2.042
1994	2.133
1995	2.226
1996	2.313
1997	2.326
1998	1.968
1999	1.917
2000	1.92
2001	1.943
2002	1.973
2003	1.987
2004	1.983
2005	2
2006	2.003
2007	2.02
2008	2.109
2009	2.217
2010	2.24
2011	2.285
2012	2.348
2013	2.398
2014	2.433
2015	2.47
2016	2.512
2017	2.545
2018	2.585
2019	2.635
2020	2.676
2021	2.718
2022	2.764
2023	2.81
2024	2.856