Year	Percent
1991	61.839
1992	62.124
1993	61.929
1994	61.966
1995	61.446
1996	61.457
1997	61.333
1998	61.579
1999	61.541
2000	61.565
2001	61.438
2002	61.303
2003	61.486
2004	61.284
2005	61.283
2006	61.304
2007	61.242
2008	61.308
2009	61.344
2010	61.317
2011	61.734
2012	62.073
2013	60.617
2014	61.297
2015	61.475
2016	61.769
2017	61.736
2018	61.763
2019	61.749
2020	61.675
2021	61.535
2022	61.685