Year	Percent
1990	72.479
1991	72.106
1992	71.506
1993	70.68
1994	70.51
1995	70.889
1996	70.632
1997	71.055
1998	71.473
1999	71.565
2000	71.915
2001	72.128
2002	72.345
2003	72.433
2004	72.483
2005	72.334
2006	72.388
2007	72.184
2008	72.001
2009	71.83
2010	71.571
2011	71.153
2012	70.85
2013	70.669
2014	70.346
2015	70.126
2016	70.118
2017	70.073
2018	70.037
2019	70.008
2020	69.982
2021	69.957
2022	69.936
2023	69.922
2024	69.915
2025	69.917
2026	69.92
2027	69.931
2028	69.948
2029	69.966
2030	69.982