Year	Percent
1991	57.068
1992	57.482
1993	56.61
1994	54.556
1995	55.797
1996	55.079
1997	58.305
1998	57.485
1999	57.649
2000	55.172
2001	54.618
2002	56.27
2003	56.985
2004	58.281
2005	59.004
2006	62.634
2007	64.635
2008	63.823
2009	53.105
2010	50.45
2011	53.352
2012	55.925
2013	57.896
2014	58.747
2015	60.081
2016	60.065
2017	60.693
2018	60.573
2019	60.355
2020	60.161
2021	59.83
2022	59.446