Year	Percent
1991	56.373
1992	56.21
1993	55.18
1994	53.769
1995	53.506
1996	53.159
1997	52.145
1998	53.165
1999	49.142
2000	48.103
2001	49.299
2002	51.572
2003	51.823
2004	52.046
2005	51.753
2006	51.588
2007	49.968
2008	49.758
2009	49.624
2010	49.667
2011	45.801
2012	48.032
2013	47.32
2014	49.354
2015	49.508
2016	50.155
2017	49.849
2018	49.373
2019	48.956
2020	48.621
2021	48.337
2022	48.073