Year	%
1987	14.4
1992	14.9
1995	14.9
2000	14.7
2003	14.3
2004	14.5
2005	14.6
2006	14.3
2007	14.4
2008	14.5
2009	14.3
2010	14.1
2011	14
2012	14
2013	13.8
2014	13.9
2015	13.9
2016	13.9
2017	13.7
2018	13.8
2019	14
2020	14
2021	13.9