Year	Percent
1990	26.329
1991	25.949
1992	25.672
1993	25.442
1994	25.227
1995	24.858
1996	24.356
1997	23.867
1998	23.404
1999	22.976
2000	22.696
2001	22.287
2002	22.081
2003	21.99
2004	21.957
2005	21.934
2006	21.932
2007	21.932
2008	21.938
2009	22.002
2010	22.216
2011	22.325
2012	22.564
2013	22.874
2014	23.181
2015	23.449
2016	23.608
2017	23.624
2018	23.641
2019	23.657
2020	23.674
2021	23.691
2022	23.708
2023	23.725
2024	23.743
2025	23.759
2026	23.776
2027	23.792
2028	23.808
2029	23.825
2030	23.843