Year	Percent
1990	71.257
1991	70.967
1992	70.642
1993	70.401
1994	70.31
1995	70.049
1996	69.868
1997	69.863
1998	69.811
1999	69.949
2000	69.874
2001	70.011
2002	70.11
2003	70.307
2004	70.483
2005	70.614
2006	70.741
2007	71.098
2008	71.301
2009	71.428
2010	71.461
2011	71.828
2012	72.047
2013	72.157
2014	72.095
2015	72.049
2016	72.052
2017	71.963
2018	71.858
2019	71.737
2020	71.602
2021	71.468
2022	71.329
2023	71.194
2024	71.073
2025	70.973
2026	70.898
2027	70.842
2028	70.81
2029	70.806
2030	70.833