Year	%
1997	12.4
1998	11.6
1999	11.7
2000	13.6
2001	12.7
2002	12.2
2003	12
2004	13.1
2005	13
2006	13.2
2007	13.3
2008	14
2009	13.9
2010	14.4
2011	14.8
2012	14.8
2013	14.9
2014	15
2015	14.8
2016	14.8
2017	14.9
2018	15
2019	15.2
2020	14.6
2021	15.2
2022	15.2