Year	Percent
1991	67.78
1992	67.619
1993	67.695
1994	67.852
1995	69.096
1996	70.552
1997	69.73
1998	69.214
1999	68.732
2000	69.412
2001	69.519
2002	71.126
2003	71.453
2004	71.018
2005	71.787
2006	72.206
2007	72.363
2008	73.307
2009	77.872
2010	79.406
2011	79.577
2012	79.833
2013	79.512
2014	75.878
2015	75.718
2016	75.858
2017	75.751
2018	75.578
2019	75.288
2020	75.328
2021	75.378
2022	75.475