Year	% of total
1990	83.6755936833412
1991	83.49200947249375
1992	83.01796017945632
1993	82.58666496198292
1994	48.64591446951207
1995	48.87105460115833
1996	49.638560844809945
1997	50.1931537490321
1998	51.76302258383908
1999	51.92800530660378
2000	53.43579575699102
2001	52.08556534517554
2002	52.7358220945726
2003	54.13202794651092
2004	54.011860028283756
2005	55.92885350988784
2006	55.83369927225775
2007	55.75051281854176
2008	55.97390468686762