Year	Percent
1990	84.377
1991	84.289
1992	84.714
1993	85.204
1994	84.482
1995	82.954
1996	83.136
1997	83.891
1998	83.848
1999	83.203
2000	82.569
2001	82.064
2002	81.633
2003	81.047
2004	81.456
2005	81.455
2006	81.759
2007	81.554
2008	81.11
2009	80.362
2010	80.125
2011	79.844
2012	80.124
2013	79.682
2014	79.459
2015	79.314
2016	79.09
2017	78.984
2018	78.876
2019	78.766
2020	78.654
2021	78.547
2022	78.44
2023	78.323
2024	78.187
2025	78.024
2026	77.849
2027	77.652
2028	77.434
2029	77.2
2030	76.953