Year	% of total
1971	0.17262432756006613
1972	0.15052770243121125
1973	0.40026603689448037
1974	0.5427715712882263
1975	0.653254079265662
1976	0.6072606111056307
1977	0.38851237049547743
1978	0.20741686941611348
1979	0.08449265335362094
1980	0.0015575448111512299
1981	0.1097693367344653
1982	0.12506158422222802
1983	0.1521004080093714
1984	0.20841084097040982
1985	0.20247785331090523
1986	0.23485435887656783
1987	0.2582405148249598
1988	0.11830001851255477
1989	0.013236679469217479
1990	0.1205876952558541
1991	0.15542459876494075
1992	0.23276092514842175
1993	0.19825359956613842
1994	0.19828598770304318
1995	0.18032440285514817
1996	0.1261891433312555
1997	0.1338067955615612
1998	0.09864217918204177
1999	0.13205385697993005
2000	0.6353575068886144
2001	0.6914356310948854
2002	0.49829685858401734
2003	0.48932427497013453
2004	0.7205498042867262
2005	0.6081863133852768
2006	0.5343235186823502
2007	0.7131795202731807
2008	0.3760705245091661
2009	0.6502756277907386
2010	0.7248800574167006
2011	1.0819421169134695
2012	0.920198353303669
2013	0.9955454252226261
2014	0.9626546522837305