Year	% of total
1960	8.79120879120879
1961	9.63855421686747
1962	19.801980198019802
1963	15.463917525773196
1964	21.50537634408602
1965	3.296703296703297
1966	41.04477611940299
1967	32.5
1968	33.333333333333336
1969	33.83458646616541
1970	2.3224653863331843
1971	3.463414634146342
1972	2.3255813953488373
1973	2.4981631153563555
1974	3.584229390681004
1975	4.246504401864319
1976	5.599513085818623
1977	6.9380733944954125
1978	5.687932359723289
1979	8.575653031049777
1980	9.802876931273307
1981	-40.149625935162085
1982	-27.320490367775836
1983	-1.084010840108401
1984	34.22562141491396
1985	47.175141242937855
1986	57.41626794258373
1987	35.91160220994475
1988	28.030788967286725
1989	24.84113229347198
1990	39.28928571428572
1991	48.4955325443787
1992	35.13782729805014
1993	41.50248062015503
1994	32.68413043478261
1995	24.202199999999998
1996	25.38093418259023
1997	25.143084479371314
1998	33.01150812064965
1999	36.93255369928401
2000	18.955823927765238
2001	20.92997679814385
2002	16.48467889908257
2003	15.995104761904763
2004	20.496443089430894
2005	21.986784232365146
2006	13.45921052631579
2007	27.02
2008	28.492894736842107
2009	23.64055181695828
2010	23.19938775510204
2011	27.934065620542086
2012	29.0068443197756
2013	23.61088319088319
2014	24.253758967001435
2015	27.53316053511706
2016	28.146084243369735