Year	Percent
1990	74.083
1991	73.401
1992	72.465
1993	71.285
1994	70.903
1995	70.582
1996	70.249
1997	70.141
1998	69.84
1999	69.921
2000	69.938
2001	69.174
2002	69.074
2003	69.338
2004	68.978
2005	69.228
2006	69.453
2007	69.312
2008	69.502
2009	68.911
2010	68.558
2011	68.292
2012	68.486
2013	68.396
2014	68.255
2015	68.187
2016	68.175
2017	68.109
2018	68.053
2019	67.976
2020	67.856
2021	67.676
2022	67.463
2023	67.229
2024	66.99
2025	66.759
2026	66.522
2027	66.298
2028	66.09
2029	65.9
2030	65.728