Year	Percent
1991	72.382
1992	72.891
1993	72.922
1994	72.421
1995	73.484
1996	74.312
1997	74.851
1998	74.541
1999	71.656
2000	69.452
2001	69.426
2002	69.964
2003	69.389
2004	64.57
2005	68.912
2006	69.393
2007	67.936
2008	71.325
2009	69.078
2010	73.194
2011	71.656
2012	69.319
2013	75.954
2014	74.915
2015	76.383
2016	76.95
2017	77.161
2018	77.456
2019	77.871
2020	78.271
2021	78.628
2022	78.988