Year	%
1977	69.96198
1978	88.2904
1988	33.35248
1990	40.72012
1991	45.18965
1992	47.75761
1993	46.56695
1994	49.6122
1998	53.01245
2001	49.13669
2004	51.7879
2005	55.63875
2006	54.8835
2008	35.11454
2011	53.9851
2013	55.26521
2014	55.90724
2016	61.86801
2017	63.63329