Year	Percent
1990	76.411
1991	76.204
1992	76.319
1993	75.546
1994	76.461
1995	76.851
1996	76.428
1997	76.06
1998	75.723
1999	75.651
2000	75.546
2001	76.156
2002	75.22
2003	74.191
2004	74.308
2005	74.4
2006	76.345
2007	76.225
2008	76.515
2009	76.81
2010	76.749
2011	76.823
2012	76.011
2013	75.838
2014	75.783
2015	75.141
2016	74.304
2017	74.43
2018	74.553
2019	74.669
2020	74.773
2021	74.835
2022	74.888
2023	74.938
2024	74.988
2025	75.042
2026	75.075
2027	75.115
2028	75.157
2029	75.202
2030	75.249