Year	Percent
1990	61.424
1991	61.394
1992	61.405
1993	61.518
1994	61.224
1995	61.302
1996	61.244
1997	61.042
1998	60.873
1999	60.93
2000	60.751
2001	61.086
2002	61.539
2003	61.527
2004	61.531
2005	61.46
2006	61.155
2007	61.054
2008	60.967
2009	61.069
2010	61.243
2011	61.326
2012	61.359
2013	61.384
2014	61.417
2015	61.594
2016	61.533
2017	61.526
2018	61.539
2019	61.554
2020	61.549
2021	61.471
2022	61.376
2023	61.29
2024	61.232
2025	61.204
2026	61.154
2027	61.13
2028	61.134
2029	61.156
2030	61.178