Year	%
1971	59.07872
1974	61.82295
1988	54.71587
1989	60.62642
1990	62.55463
1993	55.90057
1995	65.42308
1998	62.29424
1999	64.5419
2000	61.72432
2001	70.41546
2002	63.37442
2003	75.75343
2004	71.5041
2005	69.18726
2006	74.05523
2007	73.83616
2008	71.9359
2009	71.64019
2010	78.69006
2011	77.86467
2012	72.72283
2013	75.62767
2014	75.66962
2015	72.62113