Year	% of total
1970	1.4111967287511522
1971	1.3129615684294378
1972	1.278253504720812
1973	1.2795864605984086
1974	1.287722995636558
1975	1.071572078768127
1976	1.1188194495580122
1977	1.1315797257465956
1978	1.1303749082262922
1979	1.0805915346558044
1980	1.0187242804922823
1981	0.9986805448195137
1982	0.9607575542801305
1983	0.8794884205194589
1984	0.8547519389729401
1985	0.8260561694976548
1986	0.807381749477941
1987	0.7908475882645449
1988	0.8713122701605611
1989	0.9142618338210043
1990	1.5917602996254683
1991	1.499531396438613
1992	1.4285714285714286
1993	1.3268998793727382
1994	1.2804097311139564
1995	1.2594458438287155
1996	1.364256480218281
1997	1.0121457489878543
1998	1.0183299389002036
1999	1.044932079414838
2000	1.1554621848739497
2001	1.0729613733905579
2002	1.0626992561105209
2003	1.0460251046025104
2004	1.0672358591248665
2005	0.897308075772682
2006	0.7640878701050621
2007	0.7339449541284404
2008	0.611353711790393