Year	Percent
1990	75.294
1991	74.673
1992	74.757
1993	74.441
1994	74.176
1995	74.202
1996	74.208
1997	74.281
1998	74.29
1999	74.233
2000	74.227
2001	73.696
2002	73.19
2003	72.506
2004	72.254
2005	72.196
2006	72.317
2007	72.026
2008	71.797
2009	70.773
2010	69.932
2011	69.357
2012	69.347
2013	68.988
2014	68.543
2015	68.429
2016	68.558
2017	68.268
2018	67.981
2019	67.696
2020	67.413
2021	67.109
2022	66.808
2023	66.519
2024	66.255
2025	66.022
2026	65.804
2027	65.619
2028	65.46
2029	65.311
2030	65.165