Year	Percent
1990	73.353
1991	73.561
1992	72.734
1993	73.45
1994	72.811
1995	72.978
1996	73.08
1997	72.232
1998	71.988
1999	72.023
2000	71.933
2001	71.993
2002	71.326
2003	72.123
2004	72.861
2005	72.666
2006	72.266
2007	71.883
2008	71.29
2009	70.753
2010	70.586
2011	69.683
2012	69.605
2013	69.219
2014	68.739
2015	67.433
2016	67.711
2017	67.54
2018	67.331
2019	67.106
2020	66.858
2021	66.655
2022	66.393
2023	66.109
2024	65.817
2025	65.517
2026	65.315
2027	65.064
2028	64.772
2029	64.461
2030	64.148