Year	Percent
1990	80.486
1991	80.637
1992	80.299
1993	79.809
1994	79.255
1995	78.987
1996	78.611
1997	78.44
1998	78.368
1999	78.1
2000	77.568
2001	77.107
2002	76.359
2003	75.437
2004	74.538
2005	73.792
2006	73.151
2007	72.586
2008	72.066
2009	71.572
2010	71.099
2011	70.588
2012	70.121
2013	69.687
2014	69.246
2015	68.797
2016	68.467
2017	68.529
2018	68.586
2019	68.643
2020	68.697
2021	68.732
2022	68.768
2023	68.791
2024	68.783
2025	68.731
2026	68.629
2027	68.488
2028	68.321
2029	68.146
2030	67.976