Year	Percent
1990	94.237
1991	94.147
1992	94.12
1993	93.771
1994	93.565
1995	93.596
1996	93.072
1997	92.69
1998	92.809
1999	91.66
2000	89.491
2001	88.64
2002	88.236
2003	87.76
2004	89.081
2005	89.38
2006	87.552
2007	87.609
2008	87.88
2009	87.999
2010	88.882
2011	89.466
2012	89.007
2013	89.587
2014	90.033
2015	90.703
2016	91.042
2017	90.987
2018	90.934
2019	90.88
2020	90.824
2021	90.773
2022	90.718
2023	90.661
2024	90.605
2025	90.551
2026	90.501
2027	90.453
2028	90.407
2029	90.364
2030	90.322