Year	Percent
1990	75.259
1991	75.798
1992	75.856
1993	75.843
1994	75.954
1995	75.972
1996	76.062
1997	76.051
1998	76.015
1999	75.917
2000	75.786
2001	75.639
2002	76.563
2003	76.127
2004	75.906
2005	75.7
2006	75.4
2007	75.098
2008	74.793
2009	74.486
2010	74.177
2011	73.864
2012	73.55
2013	72.729
2014	71.892
2015	71.04
2016	70.709
2017	70.541
2018	70.373
2019	70.206
2020	70.038
2021	69.87
2022	69.703
2023	69.535
2024	69.368
2025	69.2
2026	69.032
2027	68.865
2028	68.697
2029	68.529
2030	68.362