Year	Percent
1991	44.027
1992	45.493
1993	47.906
1994	50.074
1995	52.398
1996	52.792
1997	54.477
1998	54.349
1999	55.084
2000	53.665
2001	54.858
2002	57.569
2003	58.938
2004	61.371
2005	62.684
2006	65.682
2007	66.488
2008	67.145
2009	67.545
2010	68.11
2011	67.099
2012	67.492
2013	65.57
2014	63.92
2015	60.411
2016	58.966
2017	59.397
2018	59.912
2019	60.428
2020	60.949
2021	61.483
2022	62.028