Year	Percent
1991	14.29
1992	14.822
1993	14.719
1994	15.21
1995	15.318
1996	14.921
1997	14.064
1998	14.216
1999	14.867
2000	14.647
2001	13.948
2002	13.272
2003	13.151
2004	13.6
2005	13.439
2006	12.614
2007	12.705
2008	12.591
2009	11.877
2010	11.922
2011	12.659
2012	12.44
2013	11.638
2014	11.826
2015	11.586
2016	14.386
2017	14.284
2018	14.055
2019	13.846
2020	13.733
2021	13.641
2022	13.527