Year	Percent
1990	67.053
1991	66.921
1992	67.539
1993	67.728
1994	68.667
1995	68.957
1996	69.348
1997	69.904
1998	69.958
1999	69.988
2000	69.916
2001	69.51
2002	69.096
2003	68.686
2004	68.155
2005	68.137
2006	68.238
2007	67.982
2008	68.154
2009	67.808
2010	67.143
2011	66.565
2012	66.401
2013	66.025
2014	66.006
2015	65.865
2016	66.285
2017	66.191
2018	66.1
2019	66.016
2020	65.94
2021	65.85
2022	65.76
2023	65.678
2024	65.614
2025	65.576
2026	65.539
2027	65.526
2028	65.526
2029	65.518
2030	65.488