Year	Percent
1991	54.303
1992	55.657
1993	53.995
1994	52.934
1995	54.798
1996	54.576
1997	58.656
1998	61.993
1999	63.013
2000	69.992
2001	71.405
2002	71.613
2003	69.012
2004	66.497
2005	65.508
2006	67.263
2007	69.009
2008	69.842
2009	67.633
2010	62.61
2011	59.939
2012	59.683
2013	59.094
2014	58.66
2015	59.903
2016	59.609
2017	60.925
2018	61.87
2019	61.979
2020	61.666
2021	61.384
2022	61.138