Year	%
1994	22.8
1995	22.9
1996	22.8
1997	23
1998	22.4
1999	22.7
2000	22.9
2003	22.7
2004	22.5
2005	22.8
2006	22.6
2007	22.9
2008	22.6
2009	22.6
2010	22.9
2011	23
2012	23
2013	22.7
2014	22.7
2015	22.9
2016	23
2017	23.1
2018	23
2019	23.1
2020	23
2021	22.9