Year	Percent
1991	8.074
1992	7.471
1993	7.904
1994	7.912
1995	7.81
1996	7.916
1997	7.791
1998	7.809
1999	7.742
2000	7.634
2001	8.335
2002	7.903
2003	5.834
2004	5.696
2005	5.728
2006	6.01
2007	5.699
2008	5.212
2009	5.138
2010	4.943
2011	4.843
2012	3.936
2013	3.92
2014	3.908
2015	3.948
2016	3.959
2017	3.958
2018	3.955
2019	3.952
2020	3.948
2021	3.942
2022	3.937