Year	% of total
1990	6.69368668566987
1991	6.8108523024762295
1992	6.694805327093201
1993	6.784941452491523
1994	6.392444902926488
1995	6.245095265953164
1996	6.327717602200305
1997	6.518839960220095
1998	6.498737808412716
1999	6.542039994551802
2000	6.91460660057721
2001	6.960515545114297
2002	6.856123365660583
2003	6.881364352849186
2004	6.855792847488499
2005	6.8766586035881305
2006	6.965233609483256
2007	6.984123386707347
2008	7.069857358788888