Year	Percent
1991	52.461
1992	50.923
1993	50.573
1994	52.771
1995	55.228
1996	56.118
1997	55.325
1998	53.532
1999	51.545
2000	52.121
2001	52.599
2002	53.344
2003	53.073
2004	52.449
2005	53.139
2006	55.14
2007	55.781
2008	53.756
2009	48.917
2010	47.923
2011	47.809
2012	46.954
2013	47.562
2014	49.405
2015	51.04
2016	51.885
2017	52.045
2018	51.607
2019	51.143
2020	50.916
2021	50.634
2022	50.279