Year	Percent
1991	45.051
1992	46.93
1993	48.663
1994	49.307
1995	49.809
1996	50.936
1997	52.031
1998	55.17
1999	56.385
2000	56.161
2001	57.273
2002	57.928
2003	57.876
2004	58.525
2005	58.728
2006	59.3
2007	60.051
2008	60.577
2009	61.437
2010	61.264
2011	61.873
2012	62.078
2013	61.949
2014	61.891
2015	61.557
2016	61.758
2017	61.848
2018	62.139
2019	62.431
2020	62.707
2021	62.99
2022	63.272