Year	Percent
1997	7.38
1998	6.23
1999	5.08
2000	9.62
2001	14.67
2002	9.81
2003	14.05
2004	10.98
2005	6.9
2006	6.11
2007	3.74
2008	4.43
2009	10.52
2010	14.41
2011	13.38
2012	11.91
2013	11.19
2014	10.71
2015	8.74
2016	7.75
2017	7.29
2018	7.2
2019	6.88
2020	9.86