Year	Percent
1990	43.597
1991	43.592
1992	44.301
1993	44.741
1994	44.805
1995	45.14
1996	45.632
1997	46.219
1998	46.746
1999	47.234
2000	47.614
2001	47.769
2002	48.171
2003	48.1
2004	48.16
2005	48.811
2006	49.565
2007	50.208
2008	48.589
2009	46.987
2010	49.304
2011	51.335
2012	52.065
2013	52.424
2014	53.205
2015	53.948
2016	54.339
2017	54.375
2018	54.391
2019	54.398
2020	54.401
2021	54.431
2022	54.458
2023	54.48
2024	54.495
2025	54.503
2026	54.538
2027	54.569
2028	54.596
2029	54.62
2030	54.642