Year	Percent
1990	83.242
1991	82.916
1992	82.578
1993	82.231
1994	81.881
1995	81.533
1996	81.129
1997	80.724
1998	80.324
1999	79.934
2000	79.56
2001	79.186
2002	79.286
2003	78.987
2004	79.381
2005	79.248
2006	79.112
2007	78.611
2008	78.605
2009	78.574
2010	77.702
2011	76.791
2012	76.243
2013	76.104
2014	75.659
2015	75.423
2016	74.945
2017	74.739
2018	74.532
2019	74.317
2020	74.091
2021	73.858
2022	73.62
2023	73.368
2024	73.095
2025	72.794
2026	72.475
2027	72.134
2028	71.775
2029	71.409
2030	71.043