Year	Percent
1990	54.389
1991	54.674
1992	54.882
1993	54.991
1994	55.067
1995	55.066
1996	55.204
1997	55.264
1998	55.399
1999	55.716
2000	55.626
2001	55.507
2002	55.336
2003	55.151
2004	54.96
2005	54.764
2006	54.611
2007	55.454
2008	54.577
2009	53.333
2010	52.039
2011	52.396
2012	53.063
2013	54.187
2014	54.924
2015	55.076
2016	57.602
2017	57.758
2018	57.929
2019	58.088
2020	58.22
2021	58.347
2022	58.445
2023	58.519
2024	58.571
2025	58.604
2026	58.636
2027	58.644
2028	58.627
2029	58.58
2030	58.504