Year	Percent
1990	75.224
1991	75.076
1992	74.883
1993	74.756
1994	74.654
1995	74.447
1996	74.458
1997	74.436
1998	74.352
1999	74.236
2000	74.092
2001	74.019
2002	73.922
2003	73.824
2004	73.798
2005	73.844
2006	73.987
2007	74.177
2008	74.325
2009	74.537
2010	74.719
2011	74.922
2012	75.097
2013	75.221
2014	75.32
2015	75.38
2016	75.414
2017	75.436
2018	75.441
2019	75.44
2020	75.44
2021	75.432
2022	75.426
2023	75.427
2024	75.443
2025	75.477
2026	75.519
2027	75.58
2028	75.651
2029	75.725
2030	75.794