Year	Percent
1991	3.293
1992	3.175
1993	3.162
1994	2.894
1995	3.309
1996	3.115
1997	2.752
1998	2.576
1999	2.466
2000	2.314
2001	2.158
2002	1.969
2003	2.123
2004	1.744
2005	1.593
2006	1.502
2007	1.317
2008	1.253
2009	1.196
2010	1.026
2011	0.886
2012	0.842
2013	0.931
2014	1.024
2015	0.921
2016	0.983
2017	0.964
2018	0.945
2019	0.931
2020	0.913
2021	0.896
2022	0.883