Year	Percent
1990	69.836
1991	70.726
1992	70.165
1993	70.936
1994	71.564
1995	71.918
1996	72.125
1997	72.055
1998	71.917
1999	71.742
2000	71.553
2001	72.022
2002	70.623
2003	70.592
2004	70.597
2005	70.551
2006	70.011
2007	70.428
2008	70.551
2009	71.651
2010	70.516
2011	69.427
2012	68.12
2013	67.36
2014	67.266
2015	67.202
2016	67.28
2017	67.116
2018	66.935
2019	66.726
2020	66.486
2021	66.246
2022	65.978
2023	65.687
2024	65.38
2025	65.062
2026	64.756
2027	64.442
2028	64.137
2029	63.863
2030	63.634