Year	Percent
1991	61.465
1992	61.653
1993	61.622
1994	61.935
1995	62.747
1996	63.074
1997	63.312
1998	63.793
1999	64.235
2000	63.572
2001	64.624
2002	64.637
2003	65.107
2004	64.746
2005	64.868
2006	64.58
2007	64.694
2008	64.15
2009	64.653
2010	64.896
2011	65.437
2012	65.484
2013	65.905
2014	65.776
2015	67.254
2016	67.304
2017	67.685
2018	67.956
2019	68.183
2020	68.34
2021	68.541
2022	68.671