Year	Percent
1991	47.104
1992	47.129
1993	47.804
1994	48.489
1995	49.031
1996	49.14
1997	50.079
1998	48.884
1999	48.547
2000	49.513
2001	49.846
2002	47.829
2003	48.235
2004	48.659
2005	49.239
2006	50.457
2007	51.471
2008	53.721
2009	53.373
2010	55.178
2011	55.85
2012	56.683
2013	56.925
2014	57.985
2015	59.737
2016	59.504
2017	59.213
2018	59.17
2019	59.059
2020	58.738
2021	58.417
2022	58.08