Year	Percent
1990	28.744
1991	28.75
1992	28.757
1993	28.766
1994	28.769
1995	28.771
1996	28.772
1997	28.771
1998	28.766
1999	28.766
2000	28.763
2001	28.76
2002	28.756
2003	28.754
2004	28.75
2005	28.746
2006	28.743
2007	28.737
2008	28.736
2009	28.741
2010	28.739
2011	28.735
2012	28.732
2013	28.729
2014	28.726
2015	28.722
2016	28.722
2017	28.72
2018	28.718
2019	28.717
2020	28.715
2021	28.713
2022	28.711
2023	28.709
2024	28.708
2025	28.706
2026	28.704
2027	28.702
2028	28.701
2029	28.699
2030	28.697