Year	Percent
1990	74.889
1991	74.929
1992	74.94
1993	74.936
1994	74.963
1995	75.017
1996	75.049
1997	75.136
1998	75.221
1999	75.285
2000	75.326
2001	75.302
2002	75.248
2003	75.19
2004	75.169
2005	75.208
2006	75.302
2007	75.444
2008	75.64
2009	75.893
2010	76.211
2011	76.571
2012	76.997
2013	77.44
2014	77.823
2015	78.09
2016	78.221
2017	78.24
2018	78.18
2019	78.09
2020	77.993
2021	77.857
2022	77.724
2023	77.569
2024	77.353
2025	77.058
2026	76.672
2027	76.229
2028	75.78
2029	75.399
2030	75.128