Year	Percent
1990	74.112
1991	73.707
1992	73.057
1993	73.005
1994	73.448
1995	73.878
1996	74.148
1997	73.928
1998	73.182
1999	73.086
2000	73.23
2001	73.589
2002	74.293
2003	73.457
2004	74.154
2005	74.729
2006	75.274
2007	75.308
2008	74.772
2009	74.1
2010	73.82
2011	73.965
2012	73.42
2013	73.451
2014	74.208
2015	74.135
2016	74.998
2017	74.864
2018	74.733
2019	74.58
2020	74.39
2021	74.177
2022	73.932
2023	73.667
2024	73.399
2025	73.139
2026	72.908
2027	72.689
2028	72.479
2029	72.277
2030	72.085