Year	Percent
1992	20.54348
1993	26.63959
1994	24.75018
1995	19.88765
1996	18.79977
1997	20.73459
1998	17.11233
1999	16.67248
2000	16.62473
2001	15.75466
2002	14.20104
2003	17.68812
2004	18.37135
2005	20.14966
2006	22.2231
2007	23.7267
2008	25.35339
2009	19.25963
2010	16.32144
2011	14.50907
2012	14.66298
2013	13.35496
2014	12.69772
2015	14.17309
2016	13.78824