Year	Percent
1991	2.948
1992	2.94
1993	3.078
1994	2.918
1995	2.704
1996	2.51
1997	2.877
1998	3.136
1999	2.908
2000	3.838
2001	5.197
2002	6.581
2003	8.025
2004	9.428
2005	8.638
2006	9.913
2007	11.029
2008	11.977
2009	13.031
2010	14.547
2011	14.257
2012	14.07
2013	13.225
2014	12.763
2015	14.565
2016	15.739
2017	12.71
2018	11.333
2019	13.641
2020	14.436
2021	14.568
2022	14.477