Year	Percent
1991	5.202
1992	5.328
1993	3.561
1994	2.052
1995	2.09
1996	2.22
1997	2.202
1998	2.209
1999	2.12
2000	2.099
2001	2.123
2002	2.247
2003	2.39
2004	2.447
2005	2.484
2006	2.576
2007	2.578
2008	2.657
2009	2.902
2010	3.007
2011	3.335
2012	3.439
2013	3.394
2014	3.567
2015	3.96
2016	4.094
2017	4.115
2018	4.138
2019	4.1
2020	4.091
2021	4.094
2022	4.085