Year	Percent
1992	74.00497
1993	37.8954
1994	37.06474
1995	38.97386
1996	35.2688
1997	34.91686
1998	30.3442
1999	42.4621
2000	56.60243
2001	45.89502
2002	46.99064
2003	48.41702
2004	52.50041
2005	53.19436
2006	50.9753
2007	49.31282
2008	57.14638
2009	41.83842
2010	44.24418
2011	46.46466
2012	44.10966
2013	38.61704
2014	39.34176
2015	28.51671
2016	31.84389