Year	Percent
1991	4.053
1992	3.607
1993	3.154
1994	2.966
1995	2.962
1996	2.894
1997	2.882
1998	2.885
1999	2.627
2000	2.76
2001	2.446
2002	2.594
2003	2.763
2004	2.824
2005	2.916
2006	2.975
2007	3.045
2008	2.935
2009	2.586
2010	3.985
2011	4.011
2012	4.057
2013	3.998
2014	3.543
2015	3.675
2016	3.739
2017	3.806
2018	3.83
2019	3.869
2020	3.922
2021	3.989
2022	4.069