Year	Percent
1991	45.641
1992	45.405
1993	47.049
1994	50.12
1995	49.337
1996	49.858
1997	51.293
1998	52.501
1999	52.496
2000	53.622
2001	52.646
2002	53.985
2003	53.253
2004	54.495
2005	56.218
2006	54.512
2007	54.014
2008	54.885
2009	51.746
2010	52.989
2011	53.806
2012	54.461
2013	53.501
2014	53.524
2015	55.252
2016	56.775
2017	57.203
2018	57.885
2019	58.592
2020	59.226
2021	59.756
2022	60.256