Year	% of total
1970	27.774298758499956
1971	27.355022714277982
1972	27.18955534071145
1973	25.214721892869907
1974	19.924446850424005
1975	24.17580278184878
1976	6.920561055918934
1977	6.821040023754388
1978	7.227796420956466
1979	7.314086413078695
1980	8.428997188024082
1981	8.612101489763017
1982	7.402224548113493
1983	6.8961689606180325
1984	6.349794841987358
1985	6.1302647883519255
1986	6.24018741591677
1987	6.01804677878819
1988	5.747402623675135
1989	5.751993342831244
1990	1.1976047904191618
1991	1.1614401858304297
1992	1.1235955056179776
1993	1.0893246187363834
1994	1.160337552742616
1995	1.1270491803278688
1996	1.0923535253227408
1997	1.085883514313919
1998	1.0773751224289911
1999	0.9718172983479106
2000	0.9652509652509652
2001	1.7679558011049725
2002	2.853437094682231
2003	4.212168486739469
2004	4.782608695652174
2005	5.080213903743315
2006	6.114649681528663
2007	7.124999999999999
2008	8.292079207920793