Year	Percent
1991	3.383
1992	2.996
1993	3.004
1994	2.451
1995	3.371
1996	2.63
1997	2.272
1998	1.862
1999	1.911
2000	1.736
2001	3.061
2002	3.013
2003	3.728
2004	2.975
2005	4.294
2006	4.472
2007	3.324
2008	3.841
2009	7.894
2010	7.541
2011	6.773
2012	8.246
2013	7.896
2014	8.154
2015	8.902
2016	8.857
2017	8.644
2018	8.211
2019	7.771
2020	7.384
2021	7.015
2022	6.675