Year	% of total
1970	2.8866968272688602
1971	5.291751315430003
1972	3.816222685623369
1973	2.446319564815038
1974	5.573064651522804
1975	5.646854767133106
1976	5.70739516147412
1977	3.041135077481267
1978	2.4667263517313405
1979	2.9997899948696607
1980	2.444763292930065
1981	2.919959518699903
1982	2.898379501741424
1983	1.4067711594299264
1984	2.8222410586615747
1985	3.5493324909089905
1986	2.8220688544287817
1987	1.9881974422918638
1988	2.7989132578508866
1989	4.628833476065894
1990	7.051282051282051
1991	6.918238993710692
1992	6.58682634730539
1993	6.547619047619048
1994	6.25
1995	5.555555555555555
1996	5.649717514124294
1997	5.555555555555555
1998	5.952380952380952
1999	6.25
2000	5.88235294117647
2001	5.681818181818182
2002	5.434782608695652
2003	5.263157894736842
2004	4.854368932038835
2005	4.854368932038835
2006	4.975124378109453
2007	4.504504504504505
2008	4.62962962962963