Year	Percent
1991	80.278
1992	83.943
1993	87.221
1994	89.552
1995	88.569
1996	88.193
1997	88.081
1998	87.753
1999	87.178
2000	86.262
2001	85.232
2002	83.53
2003	83.029
2004	80.941
2005	81.411
2006	80.382
2007	78.933
2008	76.833
2009	78.164
2010	75.634
2011	73.533
2012	72.838
2013	72.659
2014	72.607
2015	72.41
2016	72.621
2017	73.714
2018	73.639
2019	73.478
2020	73.411
2021	73.167
2022	72.943