Year	Percent
1990	67.122
1991	68.163
1992	67.584
1993	68.435
1994	69.115
1995	69.483
1996	69.661
1997	69.555
1998	69.384
1999	69.168
2000	68.927
2001	69.2
2002	67.931
2003	67.702
2004	67.671
2005	67.599
2006	66.975
2007	67.356
2008	67.363
2009	68.41
2010	67.314
2011	66.206
2012	64.974
2013	63.929
2014	63.835
2015	63.764
2016	63.842
2017	63.676
2018	63.49
2019	63.274
2020	63.02
2021	62.747
2022	62.446
2023	62.116
2024	61.757
2025	61.373
2026	60.962
2027	60.531
2028	60.097
2029	59.677
2030	59.283