Year	Percent
1990	70.073
1991	70.125
1992	70.176
1993	70.214
1994	70.296
1995	70.382
1996	70.452
1997	70.502
1998	70.527
1999	70.538
2000	69.808
2001	69.043
2002	68.268
2003	67.491
2004	66.715
2005	65.94
2006	65.241
2007	64.558
2008	63.896
2009	63.254
2010	62.624
2011	62.024
2012	61.435
2013	60.871
2014	61.046
2015	61.24
2016	61.475
2017	61.511
2018	61.561
2019	61.608
2020	61.639
2021	61.665
2022	61.675
2023	61.657
2024	61.599
2025	61.491
2026	61.355
2027	61.169
2028	60.949
2029	60.722
2030	60.506