Year	Percent
1991	71.087
1992	70.096
1993	69.585
1994	66.113
1995	62.421
1996	58.401
1997	61.677
1998	59.24
1999	69.138
2000	68.841
2001	66.303
2002	62.874
2003	60.585
2004	57.45
2005	58.793
2006	57.574
2007	56.366
2008	57.063
2009	59.858
2010	61.967
2011	61.047
2012	62.073
2013	62.551
2014	61.771
2015	62.56
2016	61.782
2017	62.23
2018	61.998
2019	61.7
2020	61.603
2021	61.551
2022	61.533