Year	% of total
1970	1.267428091797148
1971	1.3024522275380173
1972	1.4265120311306436
1973	1.493753590047302
1974	1.7776987709629113
1975	1.813376976034545
1976	1.7704781170224209
1977	1.7561908393045425
1978	1.7970493487966606
1979	1.8371832882003594
1980	1.828618808220832
1981	1.7008461116582572
1982	1.7259339756304903
1983	1.9464727879731698
1984	2.200956561436591
1985	2.1001492713499346
1986	2.004630162378769
1987	2.006634427239812
1988	2.0787290982766864
1989	2.0789880721650387
1990	1.0869565217391304
1991	1.0526315789473684
1992	1.1049723756906076
1993	1.0752688172043012
1994	1.098901098901099
1995	1.092896174863388
1996	0.975609756097561
1997	0.9345794392523363
1998	0.8695652173913043
1999	1.214574898785425
2000	1.1235955056179776
2001	1.1278195488721803
2002	1.153846153846154
2003	1.1406844106463878
2004	1.1494252873563218
2005	1.1320754716981132
2006	1.0752688172043012
2007	1.0676156583629894
2008	1.185770750988142