Year	Percent
1991	69.188
1992	67.736
1993	65.768
1994	64.809
1995	64.521
1996	63.237
1997	62.385
1998	62.132
1999	62.445
2000	62.561
2001	61.974
2002	60.862
2003	59.612
2004	58.474
2005	59.112
2006	59.792
2007	61.094
2008	61.762
2009	61.18
2010	61.565
2011	62.708
2012	62.901
2013	62.971
2014	63.011
2015	62.927
2016	63.325
2017	63.438
2018	63.354
2019	63.334
2020	63.219
2021	63.026
2022	62.818