Year	Percent
1980	2.246
1981	2.2
1982	2.22
1983	2.201
1984	2.144
1985	2.119
1986	2.117
1987	2.155
1988	2.171
1989	2.199
1990	2.194
1991	2.197
1992	1.99
1993	1.926
1994	1.914
1995	1.922
1996	1.897
1997	1.893
1998	1.926
1999	1.95
2000	1.954
2001	1.984
2002	1.984
2003	1.967
2004	1.928
2005	1.908
2006	1.887
2007	1.858
2008	1.825
2009	1.767
2010	1.679
2011	1.597
2012	1.502
2013	1.428
2014	1.399
2015	1.404
2016	1.402
2017	1.393
2018	1.379
2019	1.364
2020	1.342
2021	1.319
2022	1.295
2023	1.271
2024	1.247