Year	Percent
1991	57.686
1992	58.195
1993	57.756
1994	57.81
1995	57.496
1996	58.078
1997	60.228
1998	59.06
1999	58.293
2000	54.355
2001	52.627
2002	56.565
2003	58.102
2004	57.383
2005	57.765
2006	57.721
2007	59.502
2008	58.647
2009	51.603
2010	49.129
2011	52.228
2012	53.992
2013	55.983
2014	57.274
2015	58.429
2016	60.17
2017	60.557
2018	60.673
2019	60.7
2020	60.823
2021	60.798
2022	60.691