Year	% of total
1990	51.34151434083838
1991	56.85576099875881
1992	55.47474417994658
1993	55.26793064089879
1994	55.00192505739751
1995	55.14609863814201
1996	55.03010520948995
1997	53.09394521529834
1998	51.37786074361749
1999	50.09157150696975
2000	50.43179133900558
2001	51.141594552070735
2002	52.30054611930729
2003	54.587220465389734
2004	53.96741411090316
2005	54.81825238849604
2006	54.945376910481606
2007	54.92846648562971
2008	55.22784830198473