Year	Percent
1991	41.681
1992	39.671
1993	34.923
1994	40.091
1995	39.782
1996	40.642
1997	42.895
1998	45.022
1999	44.83
2000	43.85
2001	42.465
2002	41.504
2003	43.131
2004	43.55
2005	42.088
2006	43.092
2007	43.543
2008	42.029
2009	45.552
2010	46.835
2011	47.869
2012	43.941
2013	45.479
2014	45.696
2015	47.174
2016	47.736
2017	48.993
2018	50.017
2019	51.014
2020	51.938
2021	52.789
2022	53.629