Year	Percent
1991	4.8
1994	6.71
1995	5.71
1996	5.34
1997	5.24
1998	6.25
1999	6.07
2000	5.85
2001	4.58
2002	5.17
2003	5.73
2004	5.35
2005	5.64
2006	5.42
2007	4.45
2008	3.71
2009	5.35
2010	6.98
2011	7.79
2012	8.26
2013	9.68
2014	9.3
2015	8.66
2016	7.74
2017	6.27
2018	4.92
2019	4.18
2020	4.58