Year	Percent
1991	85.14
1992	85.508
1993	85.131
1994	85.663
1995	85.452
1996	85.196
1997	80.815
1998	80.614
1999	80.449
2000	80.124
2001	79.646
2002	79.407
2003	79.026
2004	75.601
2005	75.8
2006	75.893
2007	76.3
2008	76.416
2009	76.482
2010	76.335
2011	76.244
2012	75.974
2013	75.635
2014	75.151
2015	75.128
2016	75.183
2017	75.421
2018	75.407
2019	75.386
2020	75.365
2021	75.345
2022	75.326