Year	Percent
1991	63.127
1992	63.095
1993	62.207
1994	62.525
1995	62.559
1996	62.67
1997	62.045
1998	61.692
1999	61.07
2000	61.224
2001	60.6
2002	60.84
2003	61.174
2004	61.151
2005	60.85
2006	61.342
2007	61.516
2008	61.568
2009	60.237
2010	57.986
2011	53.857
2012	49.195
2013	47.063
2014	46.947
2015	47.762
2016	48.828
2017	49.769
2018	49.708
2019	50.117
2020	50.469
2021	50.553
2022	50.392