Year	% of total
1970	1.0404180588986047
1971	0.97794462529315
1972	0.9810397581213649
1973	1.01676782168082
1974	1.0477447146765295
1975	0.7643685769495651
1976	0.8977586583954298
1977	0.9185481882841677
1978	0.9459122710783832
1979	0.8509784659928135
1980	0.7628151271079788
1981	0.7585767513332504
1982	0.7409145173449337
1983	0.6985512564705549
1984	0.719408473727741
1985	0.7048646141086226
1986	0.7042480255728745
1987	0.6875756693470151
1988	0.8747334710361053
1989	1.013391707916724
1990	0
1991	0.49019607843137253
1992	0.7042253521126761
1993	1.2345679012345678
1994	1.183431952662722
1995	1.7142857142857144
1996	1.694915254237288
1997	2.515723270440252
1998	2.247191011235955
1999	2.5380710659898478
2000	2.358490566037736
2001	2.6548672566371683
2002	2.6923076923076925
2003	2.7027027027027026
2004	2.922077922077922
2005	2.803738317757009
2006	2.949852507374631
2007	3.4482758620689653
2008	3.4682080924855487