Year	Percent
1990	23.64
1991	23.588
1992	23.697
1993	23.843
1994	23.432
1995	23.414
1996	23.381
1997	23.43
1998	23.319
1999	22.86
2000	19.49
2001	16.51
2002	16.836
2003	17.167
2004	17.503
2005	17.844
2006	18.19
2007	19.831
2008	21.581
2009	23.44
2010	23.64
2011	21.428
2012	19.37
2013	21.442
2014	23.67
2015	25.26
2016	25.242
2017	25.357
2018	25.472
2019	25.587
2020	25.702
2021	25.817
2022	25.932
2023	26.047
2024	26.162
2025	26.277
2026	26.393
2027	26.508
2028	26.623
2029	26.738
2030	26.853
