Year	%
1987	81.57069
1988	75.10201
1989	82.03032
1990	65.14173
1994	67.69621
1995	74.04939
1998	71.38233
1999	66.15309
2000	75.69024
2001	77.19625
2002	83.54827
2003	65.92323
2004	66.62
2005	69.75378
2009	91.37392
2010	95.50707
2011	87.23396
2012	95.01196
2015	73.98987