Year	Percent
1990	53.214
1991	53.005
1992	52.784
1993	52.623
1994	52.57
1995	52.63
1996	52.633
1997	52.639
1998	52.728
1999	52.85
2000	53.309
2001	53.747
2002	54.159
2003	54.555
2004	54.957
2005	55.392
2006	55.788
2007	56.23
2008	56.692
2009	57.141
2010	57.528
2011	57.849
2012	58.123
2013	58.345
2014	58.514
2015	58.629
2016	58.653
2017	58.436
2018	58.166
2019	57.863
2020	57.541
2021	57.153
2022	56.756
2023	56.359
2024	55.97
2025	55.595
2026	55.212
2027	54.859
2028	54.543
2029	54.275
2030	54.063