Year	Percent
1990	70.958
1991	70.655
1992	70.171
1993	69.503
1994	69.365
1995	69.675
1996	69.465
1997	69.808
1998	70.146
1999	70.224
2000	70.508
2001	70.677
2002	70.85
2003	70.921
2004	70.964
2005	70.851
2006	70.891
2007	70.729
2008	70.583
2009	70.447
2010	70.24
2011	69.903
2012	69.655
2013	69.503
2014	69.239
2015	69.053
2016	69.033
2017	68.984
2018	68.944
2019	68.911
2020	68.883
2021	68.854
2022	68.832
2023	68.816
2024	68.808
2025	68.808
2026	68.808
2027	68.816
2028	68.829
2029	68.844
2030	68.858