Year	% of total
1990	84.0320140787856
1991	84.07886674896382
1992	84.15730085523515
1993	83.65813012274214
1994	84.04906490702788
1995	84.75829945479613
1996	84.90103250073516
1997	83.3376306051915
1998	82.98194556800425
1999	82.8312191224179
2000	81.86767657381529
2001	81.26517712555936
2002	81.37184551607997
2003	80.99966406440187
2004	80.96616364669998
2005	80.6215667521806
2006	79.69859694383409
2007	78.87917155911602
2008	78.06231686877982