Year	% of total
1990	46.84851079811037
1991	46.65951418421843
1992	46.71002013383092
1993	46.48672350368214
1994	46.727991550688024
1995	46.83388941195683
1996	46.492645030750715
1997	46.14361108765536
1998	46.34306499410958
1999	46.56475833674487
2000	46.26967314045657
2001	46.095110342479295
2002	46.19149059200223
2003	45.52572907008728
2004	45.71202338262999
2005	45.70328903239789
2006	45.38267644834523
2007	45.13212988046897
2008	44.6719714599049