Year	Percent
1990	72.508
1991	72.408
1992	72.31
1993	72.177
1994	72.101
1995	72.028
1996	71.955
1997	71.873
1998	71.779
1999	71.678
2000	71.581
2001	71.508
2002	71.436
2003	71.374
2004	71.327
2005	71.293
2006	71.315
2007	71.347
2008	71.389
2009	71.441
2010	71.514
2011	71.619
2012	71.73
2013	71.845
2014	71.952
2015	72.04
2016	72.112
2017	72.188
2018	72.254
2019	72.31
2020	72.359
2021	72.403
2022	72.441
2023	72.475
2024	72.513
2025	72.559
2026	72.614
2027	72.675
2028	72.746
2029	72.827
2030	72.921