Year	% of total
1990	85.7237308146399
1991	83.90860476421973
1992	84.34937611408198
1993	85.25641025641026
1994	83.94504546359593
1995	84.69350961538461
1996	84.69350961538461
1997	84.69350961538461
1998	85.16956162117452
1999	83.94737739000034
2000	86.44909688013135
2001	85.40235150404642
2002	85.64327485380117
2003	84.51152390780874
2004	82.77597840755735
2005	84.1861940167025
2006	82.63231021851712
2007	86.29586260733802
2008	85.07337983144436