Year	Percent
1990	84.367
1991	84.34
1992	83.444
1993	82.508
1994	81.531
1995	80.514
1996	79.455
1997	78.356
1998	77.215
1999	76.031
2000	74.805
2001	73.535
2002	72.225
2003	70.875
2004	69.487
2005	68.064
2006	66.607
2007	67.002
2008	67.393
2009	67.782
2010	68.17
2011	68.557
2012	68.943
2013	69.329
2014	69.711
2015	69.92
2016	70.136
2017	69.905
2018	69.673
2019	69.439
2020	69.204
2021	68.968
2022	68.73
2023	68.49
2024	68.247
2025	68
2026	67.752
2027	67.5
2028	67.248
2029	66.995
2030	66.742