Year	Percent
1991	40.409
1992	42.091
1993	42.902
1994	44.642
1995	46.202
1996	48.835
1997	51.676
1998	54.268
1999	56.541
2000	58.176
2001	60.314
2002	58.492
2003	56.667
2004	57.9
2005	56.083
2006	59.139
2007	68.552
2008	71.394
2009	73.786
2010	75.971
2011	75.093
2012	73.625
2013	74.213
2014	73.903
2015	73.044
2016	73.536
2017	73.685
2018	74.181
2019	74.649
2020	75.147
2021	75.597
2022	75.968