Year	Percent
1991	49.347
1992	49.064
1993	49.959
1994	49.374
1995	49.626
1996	49.568
1997	49.21
1998	48.309
1999	46.878
2000	46.524
2001	45.752
2002	44.658
2003	44.091
2004	42.511
2005	42.069
2006	41.139
2007	48.126
2008	54.373
2009	58.692
2010	60.182
2011	59.152
2012	59.662
2013	59.758
2014	59.718
2015	60.091
2016	59.69
2017	59.495
2018	58.826
2019	58.15
2020	57.484
2021	56.777
2022	56.103