Year	Percent
1991	90.179
1992	90.143
1993	89.919
1994	89.761
1995	89.369
1996	88.559
1997	88.097
1998	87.63
1999	86.923
2000	86.538
2001	85.805
2002	84.778
2003	83.905
2004	82.755
2005	81.411
2006	80.435
2007	79.186
2008	77.655
2009	75.949
2010	73.579
2011	72.63
2012	69.141
2013	67.689
2014	66.386
2015	65.124
2016	63.922
2017	63.212
2018	61.663
2019	60.153
2020	59.109
2021	58.097
2022	57.005