Year	% of total
1970	55.87311176958957
1971	73.76574166383212
1972	62.22473286451653
1973	49.75545616285045
1974	73.40399034924503
1975	73.65517200786479
1976	73.1007319820247
1977	54.810441639792884
1978	49.40072817147495
1979	53.164136602299465
1980	48.611535561061004
1981	54.641154695756825
1982	53.71800788069526
1983	34.08479379857886
1984	53.490880490069124
1985	60.804221253527004
1986	53.23618559450429
1987	42.29574638147028
1988	52.56741764725087
1989	69.08560755805162
1990	87.3193821624315
1991	86.99823276950265
1992	87.58076094759511
1993	88.00915331807781
1994	88.2208862168782
1995	88.50871530019367
1996	88.13301456205173
1997	87.59465478841871
1998	87.54659065994299
1999	88.21973550356053
2000	88.2
2001	88.18913086129095
2002	88.09246309246309
2003	88.07582938388624
2004	88.21056479619813
2005	88.52859135285914
2006	89.06662269129288
2007	89.22754394452508
2008	89.30447238580295