Year	% of total
1990	83.06525526392346
1991	82.83132917856389
1992	83.02448711497524
1993	83.76657890793408
1994	83.42593916246338
1995	83.42833146183352
1996	83.78440604812367
1997	83.71589607665146
1998	84.0766790519298
1999	84.03810431738515
2000	81.65388596275629
2001	81.3101918104279
2002	81.5113312441037
2003	81.07466168920726
2004	81.44208676518558
2005	81.50118951174666
2006	80.02292697882902
2007	79.17278711277616
2008	77.80270213614676