Year	% of total
1971	30.681818181818183
1972	27.450980392156865
1973	39.58333333333333
1974	35.35353535353536
1975	37.142857142857146
1976	37.719298245614034
1977	49.03846153846153
1978	81.81818181818183
1979	40.76923076923077
1980	35.483870967741936
1981	34.810126582278485
1982	10.76923076923077
1983	0.8547008547008548
1984	0.7905138339920948
1985	1.0204081632653061
1986	0.7407407407407408
1987	1.0676156583629894
1988	1.0273972602739725
1989	0.75
1990	0.6085192697768762
1991	0
1992	0.9345794392523363
1993	0.8287292817679558
1994	0.6172839506172839
1995	0.5649717514124294
1996	0.43668122270742354
1997	0.44150110375275936
1998	0.5813953488372093
1999	14.414414414414415
2000	0.33783783783783783
2001	0
2002	0
2003	0
2004	0
2005	0
2006	0
2007	0
2008	0
2009	4.267161410018553
2010	1.530612244897959
2011	0.6960556844547563
2012	0
2013	0
2014	0
2015	0