Year	% of total
1990	83.47888779214156
1991	83.50889480384998
1992	83.56519633814058
1993	83.03087101428602
1994	83.40854071721891
1995	84.24035750332351
1996	84.48436973805445
1997	82.98389133663346
1998	82.71689289733321
1999	82.64628084920783
2000	81.75801542420609
2001	81.16106004442256
2002	81.2734246748083
2003	80.90032229639358
2004	80.86584201812379
2005	80.51833650341281
2006	79.60178188774263
2007	78.78900085871614
2008	77.97748456084453