Year	Percent
1990	70.451
1991	70.413
1992	70.249
1993	69.973
1994	69.61
1995	69.176
1996	68.674
1997	68.169
1998	67.658
1999	67.135
2000	66.606
2001	66.316
2002	66.049
2003	65.85
2004	65.786
2005	65.887
2006	66.145
2007	66.538
2008	66.78
2009	67.721
2010	71.645
2011	70.923
2012	70.536
2013	70.588
2014	70.802
2015	70.18
2016	70.334
2017	70.579
2018	70.758
2019	70.85
2020	70.846
2021	70.716
2022	70.502
2023	70.239
2024	69.983
2025	69.77
2026	69.576
2027	69.429
2028	69.336
2029	69.308
2030	69.351