Year	%
1990	40.8
1995	58.2
1997	54.9
1999	54.6
2001	54.6
2002	57.3
2003	54.9
2004	52.3
2005	51.4
2006	53
2007	53
2008	50.7
2009	49.1
2010	51
2011	52.3
2012	47.6
2013	47.9
2014	50.7
2015	47.6
2016	47.9
2017	48.5
2018	46
2019	45.7
2020	43.5
2021	42.9
2022	45.1