Year	Percent
1990	74.002
1991	73.951
1992	73.878
1993	73.851
1994	73.727
1995	73.682
1996	73.676
1997	73.66
1998	73.623
1999	73.62
2000	73.614
2001	73.669
2002	73.706
2003	73.746
2004	73.779
2005	73.805
2006	73.428
2007	73.041
2008	72.643
2009	72.232
2010	71.806
2011	71.414
2012	71.017
2013	71.049
2014	71.076
2015	71.09
2016	71.117
2017	71.127
2018	71.143
2019	71.169
2020	71.211
2021	71.267
2022	71.334
2023	71.409
2024	71.483
2025	71.553
2026	71.622
2027	71.688
2028	71.749
2029	71.803
2030	71.849