Year	Percent
1991	48.409
1992	49.303
1993	47.424
1994	46.981
1995	45.532
1996	44.815
1997	44.01
1998	45.601
1999	45.132
2000	49.55
2001	49.529
2002	48.995
2003	57.885
2004	59.381
2005	59.554
2006	60.555
2007	61.093
2008	60.999
2009	60.658
2010	59.894
2011	58.572
2012	57.298
2013	56.226
2014	56.168
2015	55.808
2016	55.6
2017	55.629
2018	55.608
2019	55.576
2020	55.535
2021	55.498
2022	55.456