Year	Percent
1991	64.225
1992	65.103
1993	66.369
1994	68.331
1995	69.645
1996	70.316
1997	73.376
1998	71.398
1999	71.959
2000	68.654
2001	76.366
2002	75.234
2003	71.559
2004	69.945
2005	68.317
2006	65.619
2007	67.86
2008	70.104
2009	69.728
2010	74.287
2011	72.504
2012	72.349
2013	73.618
2014	74.122
2015	73.486
2016	74.477
2017	74.35
2018	74.783
2019	75.346
2020	75.846
2021	76.357
2022	76.871