Year	%
1986	47.4
1990	43.6
1994	43
1998	44.1
2005	43.6
2006	44.8
2009	42.1
2011	34.7
2012	34.4
2013	34
2014	34.8
2015	35.3
2016	35.9
2017	36.7
2018	37.4
2019	36.5
2020	35.8
2021	35.5
2022	34.8