Year	%
1989	19
1992	19
1994	20
1996	24.8
1998	20.7
2000	19.5
2002	18.8
2004	17.4
2005	18.8
2006	17.1
2008	18.7
2010	16.9
2012	16.8
2014	15.6
2016	18.6
2018	18
2020	18.1
2022	15.3