Year	% of total
1990	64.07263938509041
1991	62.784645987412226
1992	61.653231770684165
1993	63.6039841673889
1994	62.45182774439611
1995	63.435333670278546
1996	62.22641742893714
1997	62.18824462226145
1998	61.21837073538877
1999	60.8749331254215
2000	60.91812491023904
2001	60.5570420800405
2002	59.95835308590004
2003	59.45020524902857
2004	58.832262006764566
2005	58.585201734517355
2006	59.07883246757599
2007	60.211547872386234
2008	59.878295825662924