Year	%
1994	30.8
1995	29.9
1996	29.3
1997	29.1
1998	31.3
1999	29.7
2000	29
2003	29.5
2004	29.8
2005	28.7
2006	29.6
2007	30.6
2008	30.4
2009	31.5
2010	30.3
2011	30.8
2012	30.5
2013	30.8
2014	30.5
2015	30.5
2016	30.8
2017	29.7
2018	30.8
2019	30.2
2020	29.8
2021	30.7