Year	Percent
1991	70.308
1992	69.694
1993	71.583
1994	71.981
1995	74.081
1996	75.089
1997	75.202
1998	77.239
1999	76.875
2000	76.64
2001	76.141
2002	74.238
2003	73.408
2004	73.915
2005	73.943
2006	75.975
2007	76.093
2008	75.851
2009	69.956
2010	70.104
2011	70.59
2012	70.125
2013	69.362
2014	71.223
2015	72.668
2016	72.54
2017	72.587
2018	72.844
2019	73.315
2020	73.494
2021	73.429
2022	73.251