Year	% of total
1990	7.8795468205989305
1991	8.194812447763637
1992	8.402317187654464
1993	8.58129318526869
1994	8.560002249741366
1995	8.899604654484127
1996	9.00989119260292
1997	9.274851863717991
1998	10.048501976023056
1999	10.083720688820318
2000	10.033849487478166
2001	10.032361235030262
2002	10.028538512126055
2003	10.29919944221652
2004	10.328795893564088
2005	10.5060147813463
2006	10.95076836521186
2007	10.944668251265004
2008	11.528381785767925