Year	Percent
1990	73.227
1991	73.249
1992	73.216
1993	73.19
1994	73.133
1995	73.04
1996	72.95
1997	72.874
1998	72.849
1999	72.847
2000	72.786
2001	72.749
2002	72.708
2003	72.65
2004	72.568
2005	72.476
2006	72.402
2007	72.313
2008	72.262
2009	72.241
2010	72.481
2011	72.8
2012	73.183
2013	73.598
2014	73.909
2015	73.378
2016	73.202
2017	73.241
2018	73.205
2019	73.109
2020	72.964
2021	72.783
2022	72.553
2023	72.283
2024	71.99
2025	71.687
2026	71.398
2027	71.107
2028	70.82
2029	70.541
2030	70.27