Year	Percent
1991	6.224
1992	4.937
1993	4.51
1994	4.356
1995	5.807
1996	4.826
1997	5.854
1998	5.016
1999	6.141
2000	5.491
2001	4.955
2002	4.403
2003	3.937
2004	3.594
2005	3.249
2006	3.121
2007	3.169
2008	3.329
2009	3.464
2010	3.554
2011	3.651
2012	3.86
2013	4.224
2014	4.356
2015	4.748
2016	3.076
2017	3.189
2018	3.24
2019	3.191
2020	3.156
2021	3.147
2022	3.137