Year	Percent
1991	44.705
1992	45.435
1993	44.814
1994	45.162
1995	49.123
1996	53.008
1997	52.007
1998	52.995
1999	54.79
2000	55.885
2001	55.784
2002	55.579
2003	55.457
2004	57.088
2005	57.593
2006	58.336
2007	59.057
2008	58.487
2009	57.279
2010	56.879
2011	56.404
2012	55.007
2013	56.013
2014	53.992
2015	55.325
2016	56.254
2017	55.957
2018	55.697
2019	55.396
2020	55.103
2021	54.869
2022	54.636