Year	Percent
1991	28.51306
1992	27.95939
1993	27.60696
1994	27.21846
1995	26.6052
1996	26.30832
1997	25.92817
1998	25.08709
1999	22.13951
2000	21.61676
2001	21.80636
2002	19.74779
2003	18.24117
2004	19.12958
2005	19.99176
2006	18.86159
2007	18.025
2008	18.68872
2009	20.91045
2010	20.77818
2011	21.59647
2012	20.97049
2013	19.58579
2014	18.7644
2015	18.11051
2016	18.67878
2017	18.57483
2018	16.70833
2019	16.2874