Year	Percent
1991	50.651
1992	49.319
1993	49.914
1994	51.014
1995	50.709
1996	52.462
1997	53.231
1998	53.584
1999	52.41
2000	52.427
2001	51.665
2002	51.422
2003	51.634
2004	52.372
2005	51.89
2006	51.857
2007	50.813
2008	49.346
2009	46.392
2010	45.095
2011	44.73
2012	44.978
2013	44.441
2014	44.01
2015	44.426
2016	44.539
2017	44.941
2018	45.063
2019	44.975
2020	44.786
2021	44.603
2022	44.415