Year	Percent
1990	80.474
1991	80.744
1992	80.09
1993	80.175
1994	79.308
1995	79.114
1996	78.892
1997	78.486
1998	78.361
1999	78.114
2000	77.665
2001	77.231
2002	76.626
2003	76.595
2004	75.809
2005	75.034
2006	75.358
2007	75.751
2008	75.39
2009	75.23
2010	74.307
2011	74.627
2012	74.388
2013	74.102
2014	74.123
2015	74.226
2016	74.427
2017	74.144
2018	73.86
2019	73.556
2020	73.217
2021	72.827
2022	72.41
2023	71.97
2024	71.508
2025	71.026
2026	70.533
2027	70.029
2028	69.523
2029	69.023
2030	68.534