Year	Percent
1991	77.452
1992	76.804
1993	76.384
1994	75.562
1995	74.057
1996	73.537
1997	73.544
1998	71.052
1999	68.914
2000	69.47
2001	68.491
2002	66.285
2003	65.35
2004	66.142
2005	66.42
2006	66.654
2007	67.082
2008	66.533
2009	64.793
2010	64.672
2011	65.294
2012	65.819
2013	66.244
2014	66.058
2015	66.084
2016	65.835
2017	65.747
2018	65.618
2019	65.234
2020	64.675
2021	64.056
2022	63.345