Year	Percent
1990	71.943
1991	71.866
1992	71.771
1993	71.655
1994	71.591
1995	71.542
1996	71.506
1997	71.434
1998	71.38
1999	71.31
2000	71.229
2001	71.189
2002	71.176
2003	71.178
2004	71.186
2005	71.191
2006	71.206
2007	71.22
2008	71.231
2009	71.227
2010	71.249
2011	71.284
2012	71.319
2013	71.355
2014	71.385
2015	71.39
2016	71.37
2017	71.369
2018	71.366
2019	71.362
2020	71.356
2021	71.345
2022	71.336
2023	71.33
2024	71.33
2025	71.337
2026	71.348
2027	71.366
2028	71.393
2029	71.434
2030	71.487