Year	Percent
1991	59.374
1992	59.745
1993	61.366
1994	61.358
1995	60.568
1996	60.042
1997	60.124
1998	59.477
1999	59.726
2000	59.668
2001	59.808
2002	59.945
2003	59.798
2004	60.452
2005	60.219
2006	58.365
2007	57.069
2008	56.652
2009	56.506
2010	56.881
2011	56.739
2012	55.485
2013	54.646
2014	54.942
2015	54.055
2016	54.636
2017	54.19
2018	54.089
2019	53.867
2020	53.604
2021	53.351
2022	53.107