Year	Percent
1991	4.586
1992	4.591
1993	4.695
1994	4.435
1995	4.17
1996	3.639
1997	3.449
1998	3.26
1999	3.339
2000	3.135
2001	3.104
2002	2.957
2003	2.673
2004	3.01
2005	3.011
2006	2.671
2007	2.452
2008	2.567
2009	2.511
2010	2.335
2011	2.155
2012	2.382
2013	1.787
2014	1.605
2015	1.425
2016	1.468
2017	1.466
2018	1.445
2019	1.416
2020	1.384
2021	1.357
2022	1.33