Year	Percent
1990	48.395
1991	48.298
1992	48.307
1993	48.295
1994	48.333
1995	48.321
1996	48.363
1997	48.417
1998	48.469
1999	48.564
2000	48.681
2001	48.738
2002	48.832
2003	48.949
2004	49.074
2005	49.194
2006	49.352
2007	49.525
2008	49.73
2009	49.97
2010	50.243
2011	50.59
2012	50.981
2013	51.391
2014	51.795
2015	52.168
2016	52.449
2017	52.569
2018	52.665
2019	52.775
2020	52.921
2021	53.091
2022	53.288
2023	53.498
2024	53.7
2025	53.881
2026	54.042
2027	54.184
2028	54.313
2029	54.436
2030	54.558