Year	Percent
1991	62.882
1992	65.655
1993	65.257
1994	65.485
1995	66.351
1996	66.056
1997	67.451
1998	66.799
1999	67.378
2000	66.644
2001	67.946
2002	65.735
2003	65.264
2004	66.004
2005	65.61
2006	65.457
2007	64.878
2008	64.368
2009	64.021
2010	62.774
2011	61.944
2012	59.979
2013	56.943
2014	56.325
2015	60.071
2016	59.769
2017	59.505
2018	58.587
2019	57.756
2020	56.658
2021	55.557
2022	54.447