Year	% of total
1990	8.493670684986453
1991	8.751004232535452
1992	8.970566653366312
1993	9.120591669214129
1994	7.896958461661785
1995	7.7468270891889395
1996	7.679995630489985
1997	7.505918755390071
1998	7.134647805085134
1999	6.813695445459696
2000	6.556620564393199
2001	6.650586724356196
2002	6.465257798452728
2003	6.535193728626043
2004	6.543613763618514
2005	6.430418882952871
2006	6.684588695452177
2007	6.697476508934294
2008	6.81026648994788