Year	% of total
1990	83.84319427782017
1991	83.73615090867041
1992	83.80333029767296
1993	83.27741089396397
1994	83.39059382931248
1995	83.6843819299909
1996	83.53975528225708
1997	82.63179863923841
1998	82.36321514191613
1999	82.2726066604339
2000	81.30159852726611
2001	81.34559005443492
2002	81.61670841638723
2003	81.27981189629023
2004	80.97731793121861
2005	80.68592669333545
2006	79.8324656680602
2007	79.92420075016763
2008	79.41099540155926