Year	Percent
1991	68.526
1992	67.02
1993	68.232
1994	63.235
1995	60.779
1996	63.117
1997	62.506
1998	59.848
1999	66.002
2000	63.639
2001	63.516
2002	65.474
2003	62.682
2004	61.595
2005	59.061
2006	62.296
2007	60.353
2008	61.628
2009	62.399
2010	61.277
2011	62.551
2012	61.002
2013	61.181
2014	61.598
2015	62.576
2016	63.177
2017	63.364
2018	63.325
2019	63.261
2020	63.202
2021	63.066
2022	62.936