Year	Percent
1990	69.379
1991	69.831
1992	70.437
1993	71.15
1994	71.55
1995	71.889
1996	72.051
1997	72.076
1998	71.923
1999	71.908
2000	71.734
2001	71.57
2002	71.342
2003	71.172
2004	70.913
2005	70.589
2006	70.08
2007	69.463
2008	68.957
2009	68.659
2010	68.234
2011	68.11
2012	68.083
2013	68.124
2014	68.147
2015	68.119
2016	68.06
2017	67.991
2018	67.907
2019	67.801
2020	67.682
2021	67.474
2022	67.255
2023	67.022
2024	66.77
2025	66.496
2026	66.151
2027	65.792
2028	65.432
2029	65.088
2030	64.765