Year	Percent
1990	72.063
1991	72.004
1992	71.641
1993	73.325
1994	73.358
1995	72.998
1996	71.764
1997	70.945
1998	70.198
1999	69.674
2000	69.683
2001	69.39
2002	68.291
2003	67.966
2004	68.505
2005	68.774
2006	69.258
2007	69.889
2008	69.938
2009	68.992
2010	69.36
2011	69.25
2012	69.427
2013	69.6
2014	69.519
2015	69.506
2016	69.287
2017	69.145
2018	69.016
2019	68.898
2020	68.788
2021	68.682
2022	68.593
2023	68.511
2024	68.424
2025	68.326
2026	68.222
2027	68.11
2028	68.004
2029	67.927
2030	67.889