Year	Percent
1990	64.833
1991	65.663
1992	66.493
1993	67.301
1994	68.029
1995	68.322
1996	68.468
1997	68.549
1998	68.792
1999	69.111
2000	69.205
2001	69.476
2002	69.705
2003	69.674
2004	69.73
2005	69.921
2006	70.005
2007	70.068
2008	70.001
2009	69.888
2010	70.091
2011	69.992
2012	70.087
2013	70.07
2014	70.009
2015	69.87
2016	69.796
2017	69.971
2018	70.131
2019	70.217
2020	70.2
2021	70.087
2022	69.875
2023	69.589
2024	69.265
2025	68.929
2026	68.582
2027	68.221
2028	67.866
2029	67.534
2030	67.24