Year	Percent
1990	68.695
1991	69.211
1992	69.894
1993	70.848
1994	71.268
1995	71.621
1996	71.844
1997	71.759
1998	71.401
1999	70.828
2000	71.051
2001	71.069
2002	71.092
2003	71.056
2004	70.909
2005	70.888
2006	70.87
2007	70.787
2008	70.718
2009	70.676
2010	70.572
2011	70.474
2012	70.44
2013	70.412
2014	70.413
2015	70.476
2016	70.843
2017	70.795
2018	70.737
2019	70.638
2020	70.48
2021	70.295
2022	70.058
2023	69.809
2024	69.606
2025	69.483
2026	69.456
2027	69.502
2028	69.582
2029	69.64
2030	69.648