Year	% of total
1990	47.93202329933472
1991	47.99392292128793
1992	48.3086921263294
1993	48.07621740324155
1994	48.35653608795724
1995	48.363647479128005
1996	47.83434632818754
1997	47.07370794706787
1998	46.899275173386776
1999	46.62427230453987
2000	45.973975117865585
2001	45.62727156165357
2002	45.47333849851944
2003	44.83434761950604
2004	44.73184826023968
2005	44.71870049481854
2006	44.03293587311805
2007	43.394513209849606
2008	42.86147246618454