Year	Percent
1989	91.57676
1990	99.91402
1991	84.21641
1992	75.85799
1993	70.8021
1994	62.40151
1995	62.32893
1996	55.25029
1997	47.55464
1998	40.95376
1999	36.75018
2000	35.93774
2001	39.95189
2002	34.94389
2003	37.35425
2004	58.30326
2005	58.55224
2006	57.97371
2007	63.06073
2008	67.98363
2009	57.205
2010	60.23514
2011	64.18434
2012	60.69015
2013	58.51485
2014	53.90196
2015	47.18292
2016	47.11927
2017	46.36815