Year	Percent
1991	54.986
1992	54.663
1993	54.31
1994	53.475
1995	54.757
1996	54.927
1997	55.457
1998	54.028
1999	54.122
2000	53.579
2001	63.636
2002	61.571
2003	58.413
2004	58.053
2005	59.363
2006	56.985
2007	54.298
2008	56.945
2009	60.743
2010	62.587
2011	65.075
2012	67.395
2013	68.739
2014	72.895
2015	75.186
2016	75.537
2017	73.291
2018	73.119
2019	73.264
2020	73.299
2021	73.286
2022	73.328