Year	Percent
1991	27.91319
1992	27.47027
1993	24.62844
1994	23.9461
1995	23.19551
1996	22.66041
1997	21.24457
1998	20.99729
1999	20.59686
2000	20.85386
2001	20.77111
2002	20.12786
2003	20.38672
2004	18.48736
2005	18.10529
2006	18.2774
2007	18.39804
2008	18.14989
2009	18.01729
2010	17.81642
2011	17.59009
2012	18.23451
2013	18.24741
2014	18.42259
2015	17.7449
2016	16.63298
2017	16.77728
2018	16.22877
2019	15.22505