Year	Percent
1990	75.741
1991	75.68
1992	75.229
1993	74.777
1994	74.318
1995	73.852
1996	73.502
1997	73.185
1998	72.891
1999	72.618
2000	72.361
2001	72.1
2002	70.51
2003	70.929
2004	72.209
2005	71.527
2006	70.38
2007	72.767
2008	72.328
2009	70.82
2010	70.554
2011	70.731
2012	69.855
2013	68.905
2014	70.945
2015	71.669
2016	70.398
2017	70.481
2018	70.586
2019	70.658
2020	70.662
2021	70.634
2022	70.538
2023	70.397
2024	70.255
2025	70.141
2026	70.071
2027	70.03
2028	70.006
2029	69.976
2030	69.93