Year	Percent
1990	85.699
1991	84.644
1992	83.255
1993	82.662
1994	82.348
1995	82.068
1996	82.514
1997	82.842
1998	83.094
1999	81.868
2000	80.181
2001	79.805
2002	79.206
2003	78.216
2004	77.177
2005	76.157
2006	75.402
2007	74.326
2008	74.115
2009	72.703
2010	72.783
2011	72.854
2012	72.621
2013	72.225
2014	71.638
2015	70.889
2016	70.599
2017	70.147
2018	69.686
2019	69.217
2020	68.747
2021	68.975
2022	69.22
2023	69.465
2024	69.691
2025	69.879
2026	69.881
2027	69.871
2028	69.84
2029	69.784
2030	69.698