Year	Percent
1990	74.745
1991	74.288
1992	73.549
1993	72.509
1994	72.282
1995	72.759
1996	72.424
1997	72.959
1998	73.482
1999	73.601
2000	74.043
2001	74.314
2002	74.594
2003	74.716
2004	74.796
2005	74.626
2006	74.709
2007	74.461
2008	74.233
2009	74.017
2010	73.674
2011	73.094
2012	72.661
2013	72.396
2014	71.914
2015	71.57
2016	71.545
2017	71.461
2018	71.389
2019	71.326
2020	71.271
2021	71.216
2022	71.17
2023	71.132
2024	71.102
2025	71.079
2026	71.055
2027	71.038
2028	71.025
2029	71.012
2030	70.995