Year	%
1997	12.8
2000	10.83
2001	10.6
2002	7.68
2003	7.57
2004	6.97
2005	6.67
2006	6.36
2007	5.31
2008	4.96
2009	5.29
2010	4.95
2011	4.49
2012	4.44
2013	4.88
2014	5.36
2015	5.11
2016	5.04
2017	2.84
2018	5.35
2019	5.35
2020	5.16
2021	5.2