Year	Percent
1990	11.527
1991	11.598
1992	11.655
1993	11.741
1994	11.632
1995	11.565
1996	11.55
1997	10.876
1998	10.236
1999	9.63
2000	9.056
2001	8.513
2002	8
2003	8.062
2004	8.125
2005	8.188
2006	8.252
2007	8.316
2008	8.445
2009	8.576
2010	8.709
2011	8.843
2012	8.98
2013	8.949
2014	8.903
2015	8.84
2016	8.812
2017	8.827
2018	8.842
2019	8.857
2020	8.872
2021	8.888
2022	8.903
2023	8.918
2024	8.933
2025	8.948
2026	8.963
2027	8.979
2028	8.994
2029	9.009
2030	9.024