Year	Percent
1991	3.15
1992	3.268
1993	3.138
1994	4.273
1995	3.146
1996	3.073
1997	3.233
1998	4.051
1999	4.114
2000	3.95
2001	4.137
2002	3.898
2003	3.929
2004	4.747
2005	5.104
2006	3.45
2007	3.378
2008	3.529
2009	3.881
2010	3.922
2011	3.948
2012	4.585
2013	4.375
2014	4.303
2015	3.884
2016	3.61
2017	3.569
2018	3.526
2019	3.48
2020	3.464
2021	3.441
2022	3.424