Year	Percent
1990	69.274
1991	69.79
1992	70.202
1993	70.882
1994	70.846
1995	70.623
1996	70.412
1997	70.111
1998	69.783
1999	69.477
2000	69.151
2001	68.893
2002	68.656
2003	68.412
2004	68.183
2005	68.042
2006	67.946
2007	67.819
2008	67.702
2009	67.647
2010	67.51
2011	67.384
2012	67.21
2013	66.951
2014	66.638
2015	66.298
2016	66.068
2017	65.947
2018	65.826
2019	65.705
2020	65.584
2021	65.464
2022	65.343
2023	65.222
2024	65.101
2025	64.98
2026	64.859
2027	64.739
2028	64.618
2029	64.497
2030	64.376