Year	Percent
1990	72.485
1991	72.604
1992	72.35
1993	72.205
1994	73.257
1995	72.205
1996	71.908
1997	71.56
1998	71.173
1999	73.164
2000	72.615
2001	71.389
2002	71.567
2003	72.067
2004	72.543
2005	72.961
2006	73.252
2007	73.468
2008	74.118
2009	74.757
2010	75.794
2011	75.734
2012	75.875
2013	75.837
2014	74.835
2015	73.636
2016	73.569
2017	73.718
2018	73.803
2019	73.852
2020	73.887
2021	73.919
2022	73.95
2023	73.952
2024	73.882
2025	73.723
2026	73.496
2027	73.205
2028	72.899
2029	72.65
2030	72.499