Year	Percent
1990	91.104
1991	90.642
1992	90.076
1993	89.41
1994	88.66
1995	87.836
1996	87.117
1997	86.327
1998	85.459
1999	84.638
2000	83.771
2001	83.063
2002	82.402
2003	81.795
2004	81.247
2005	80.755
2006	80.298
2007	79.866
2008	79.455
2009	79.072
2010	78.723
2011	78.276
2012	77.863
2013	77.47
2014	77.076
2015	77.474
2016	77.823
2017	77.876
2018	77.898
2019	77.863
2020	77.758
2021	77.581
2022	77.346
2023	77.071
2024	76.785
2025	76.508
2026	76.231
2027	75.965
2028	75.717
2029	75.501
2030	75.322