Year	Percent
1991	77.412
1992	76.658
1993	74.382
1994	74.473
1995	74.323
1996	74.146
1997	74.772
1998	74.038
1999	72.506
2000	72.512
2001	68.615
2002	67.209
2003	67.284
2004	70.727
2005	72.361
2006	72.544
2007	72.444
2008	71.114
2009	70.501
2010	71.555
2011	58.353
2012	74.48
2013	62.552
2014	54.465
2015	53.276
2016	53.864
2017	62.873
2018	66.001
2019	67.828
2020	70.375
2021	71.644
2022	72.28