Year	Percent
1990	68.198
1991	68.501
1992	68.708
1993	68.795
1994	68.785
1995	68.552
1996	68.629
1997	68.58
1998	68.459
1999	68.249
2000	68.025
2001	67.964
2002	67.801
2003	67.703
2004	67.546
2005	67.356
2006	67.263
2007	67.147
2008	66.915
2009	66.819
2010	66.648
2011	66.481
2012	66.272
2013	66.08
2014	65.927
2015	65.778
2016	65.487
2017	65.428
2018	65.375
2019	65.329
2020	65.292
2021	65.25
2022	65.216
2023	65.192
2024	65.177
2025	65.171
2026	65.161
2027	65.162
2028	65.171
2029	65.187
2030	65.208