Year	% of total
1990	9.547919030058633
1991	9.843212639816938
1992	10.12040292599707
1993	10.288319460822716
1994	10.458535472529695
1995	10.134830425328285
1996	9.90554023362555
1997	9.640931742665748
1998	8.95370092440563
1999	8.393329101553231
2000	7.8935626060929325
2001	8.044868106631656
2002	7.680134053707867
2003	7.786283653662628
2004	7.780347357311194
2005	7.623696735949404
2006	8.027180169306131
2007	8.084239788738666
2008	8.263168318833285