Year	%
1997	13.4
1998	15.3
1999	13.9
2000	13
2001	12.8
2002	13.5
2003	10.3
2004	11.9
2005	12.6
2006	12.9
2007	11.9
2008	12.1
2009	12
2010	9.8
2011	8.5
2012	7.5
2013	6.8
2014	4.7
2015	5.2
2016	4.2
2017	4.5
2018	3.8
2019	4.5
2021	4.3