Year	Percent
1990	73.793
1991	73.859
1992	74.065
1993	74.351
1994	74.632
1995	74.657
1996	74.042
1997	73.134
1998	72.116
1999	71.149
2000	72.14
2001	70.975
2002	70.948
2003	71.047
2004	71.302
2005	72.138
2006	72.078
2007	71.97
2008	71.865
2009	71.799
2010	71.975
2011	72.88
2012	73.194
2013	73.61
2014	72.333
2015	72.65
2016	72.787
2017	72.846
2018	72.851
2019	72.766
2020	72.572
2021	72.288
2022	71.887
2023	71.422
2024	70.973
2025	70.59
2026	70.288
2027	70.059
2028	69.874
2029	69.677
2030	69.44