Year	Percent
1991	57.509
1992	57.907
1993	58.478
1994	58.849
1995	59.242
1996	59.541
1997	59.957
1998	60.307
1999	60.695
2000	60.868
2001	61.086
2002	61.14
2003	61.237
2004	60.106
2005	60.174
2006	60.097
2007	59.93
2008	59.855
2009	59.671
2010	59.165
2011	58.942
2012	58.826
2013	58.752
2014	58.809
2015	58.788
2016	58.708
2017	58.563
2018	58.449
2019	58.386
2020	58.305
2021	58.141
2022	57.964