Year	% of total
1990	70.01926618318534
1991	69.07028260252365
1992	68.74398883246786
1993	67.55720072982567
1994	66.9885636419988
1995	67.0599176710941
1996	66.63252731631901
1997	66.384898493342
1998	67.32483569798761
1999	67.0615813442033
2000	66.68478478988794
2001	66.14680207066282
2002	65.68568672804201
2003	64.88818104364628
2004	64.05548193527075
2005	64.04598605042102
2006	62.46521461010276
2007	63.010445443968834
2008	62.69857109725658