Year	Percent
1991	82.147
1992	82.437
1993	82.747
1994	81.12
1995	77.925
1996	79.418
1997	81.369
1998	81.425
1999	81.565
2000	80.75
2001	80.284
2002	79.557
2003	78.922
2004	78.927
2005	78.707
2006	78.984
2007	78.748
2008	78.024
2009	76.039
2010	75.8
2011	75.683
2012	76.179
2013	75.769
2014	75.639
2015	75.935
2016	76.047
2017	76.367
2018	76.298
2019	76.244
2020	76.112
2021	75.984
2022	75.856