Year	Percent
1991	5.466
1992	5.135
1993	4.926
1994	4.968
1995	4.966
1996	4.981
1997	5.037
1998	5.279
1999	5.586
2000	5.344
2001	3.188
2002	2.205
2003	1.762
2004	1.407
2005	1.164
2006	0.914
2007	0.765
2008	0.65
2009	0.514
2010	0.447
2011	0.491
2012	0.488
2013	0.511
2014	0.538
2015	0.547
2016	0.591
2017	0.599
2018	0.588
2019	0.588
2020	0.576
2021	0.56
2022	0.539