Year	Percent
1990	26.278
1991	26.597
1992	26.832
1993	26.857
1994	27.041
1995	26.831
1996	26.735
1997	26.833
1998	26.851
1999	26.832
2000	26.65
2001	26.52
2002	26.462
2003	26.392
2004	26.305
2005	26.203
2006	26.128
2007	25.972
2008	25.909
2009	25.967
2010	25.942
2011	25.8
2012	25.752
2013	25.744
2014	25.672
2015	25.585
2016	25.476
2017	25.449
2018	25.415
2019	25.357
2020	25.269
2021	25.211
2022	25.125
2023	25.027
2024	24.944
2025	24.892
2026	24.925
2027	24.986
2028	25.063
2029	25.138
2030	25.2