Year	Percent
1990	21.371
1991	22.973
1992	23.667
1993	23.593
1994	23.248
1995	22.398
1996	22.058
1997	21.107
1998	20.753
1999	22.411
2000	21.367
2001	20.722
2002	19.867
2003	19.334
2004	18.336
2005	17.731
2006	17.201
2007	16.6
2008	15.42
2009	14.31
2010	11.27
2011	8.29
2012	8.01
2013	10.64
2014	13.12
2015	12.08
2016	15.52
2017	14.771
2018	14.022
2019	13.273
2020	12.524
2021	11.775
2022	11.027
2023	10.278
2024	9.529
2025	8.78
2026	8.031
2027	7.282
2028	6.533
2029	5.784
2030	5.035