Year	% of total
1990	47.38531850546435
1991	47.12063695400371
1992	46.908839651987115
1993	46.41685706791336
1994	46.34213918108807
1995	47.080178147070164
1996	47.611608174648204
1997	45.81465917698758
1998	46.00584699254476
1999	46.47245765175396
2000	45.98102579596777
2001	45.45656473704768
2002	44.99919192051698
2003	44.6677320994503
2004	45.10519246134118
2005	45.24970744694786
2006	44.07320277779398
2007	42.817018943541306
2008	42.053736145059005