Year	Percent
1991	73.112
1992	72.498
1993	70.938
1994	71.33
1995	71.38
1996	71.523
1997	71.124
1998	70.642
1999	69.088
2000	67.806
2001	65.344
2002	62.63
2003	61.467
2004	62.307
2005	62.753
2006	62.49
2007	62.359
2008	62.266
2009	60.399
2010	62.384
2011	64.664
2012	64.477
2013	64.797
2014	64.791
2015	65.118
2016	65.264
2017	64.915
2018	64.683
2019	64.427
2020	64.152
2021	63.86
2022	63.571