Year	%
1990	48.2
1992	54.7
1997	61.7
1999	60.5
2000	64.2
2001	60.6
2002	62.4
2004	59.5
2005	62
2006	60.1
2007	58.7
2008	54.8
2009	53.2
2011	50.6
2012	50.6
2013	51.9
2014	52.3
2015	51.2
2016	49.4
2017	49
2018	47.5
2019	47.3
2020	49
2021	46.7