Year	% of total
1990	6.545597438184179
1991	6.732152477015584
1992	6.31349656363452
1993	6.4812174069941175
1994	6.400419999414335
1995	6.648726995457195
1996	7.014935631427251
1997	6.902508403763209
1998	7.033719537957594
1999	7.2114094743812425
2000	7.289124352205121
2001	7.544784846725582
2002	7.056874283485473
2003	7.411715585111537
2004	7.678482241772754
2005	7.696059065440887
2006	7.844076596976172
2007	8.029822578253166
2008	8.037645130666412