Year	Percent
1990	17.637
1991	17.503
1992	17.408
1993	17.146
1994	16.78
1995	16.404
1996	16.047
1997	15.753
1998	15.538
1999	15.241
2000	14.875
2001	14.631
2002	14.351
2003	14.1
2004	13.8
2005	13.489
2006	13.218
2007	12.967
2008	12.8
2009	10.22
2010	10.48
2011	8.35
2012	8.98
2013	10.34
2014	9.83
2015	10.54
2016	10.93
2017	10.619
2018	10.308
2019	9.997
2020	9.686
2021	9.375
2022	9.063
2023	8.752
2024	8.441
2025	8.13
2026	7.819
2027	7.508
2028	7.197
2029	6.886
2030	6.575