Year	% of total
1990	6.537690934336802
1991	6.63945848927746
1992	6.088744504063434
1993	6.167569460302422
1994	5.975686788518326
1995	6.2527563219483335
1996	6.506464202374539
1997	6.317836694957115
1998	6.503460657612199
1999	6.688488284573153
2000	6.824311644558085
2001	7.1610570848209125
2002	6.561221397844264
2003	6.9714562317876405
2004	7.30111474884894
2005	7.4443410939643275
2006	7.703644849511659
2007	7.969542729005172
2008	7.865780794167021