Year	% of total
1990	8.35528605619017
1991	8.685246995767963
1992	8.9716341991625
1993	9.144371177454088
1994	9.079704128529192
1995	8.896162700006235
1996	8.657125784395326
1997	8.393144087780746
1998	7.622228292183026
1999	7.157973260228864
2000	6.490580763298755
2001	6.680603732668968
2002	6.4706180884899736
2003	6.524964966895778
2004	6.668483888615348
2005	6.634810060500447
2006	7.132797972269157
2007	7.030210908527658
2008	7.15616156662148