Year	Percent
1991	78.101
1992	76.551
1993	76.509
1994	77.089
1995	77.342
1996	75.341
1997	76.211
1998	76.742
1999	74.374
2000	77.902
2001	77.053
2002	77.503
2003	75.292
2004	77.551
2005	78.502
2006	80.038
2007	79.736
2008	78.428
2009	78.111
2010	77.648
2011	77.492
2012	77.572
2013	77.335
2014	77.58
2015	78.727
2016	78.422
2017	78.822
2018	78.551
2019	78.271
2020	77.976
2021	77.69
2022	77.393