Year	%
1986	3.9
1989	4.2
1992	4.3
1996	4.3
1997	4
2000	3.7
2001	4.1
2002	3.8
2003	3.8
2004	3.9
2005	4.1
2006	3.9
2007	4.4
2008	4.6
2009	4.5
2010	4.6
2011	4.7
2012	4.9
2013	4.8
2014	5.1
2015	5
2016	4.9
2017	5.9
2018	5.8
2019	6
2020	6.2
2021	6.5
2022	6.6