Year	Percent
1991	47.584
1992	47.341
1993	48.347
1994	48.036
1995	48.759
1996	49.784
1997	48.494
1998	49.19
1999	49.36
2000	49.724
2001	49.919
2002	50.621
2003	51.323
2004	52.12
2005	51.232
2006	51.171
2007	51.428
2008	54.868
2009	60.415
2010	63.68
2011	64.891
2012	65.81
2013	64.536
2014	64.43
2015	63.075
2016	62.453
2017	63.199
2018	63.5
2019	63.759
2020	63.95
2021	64.132
2022	64.235