Year	% of total
1990	51.34151434083838
1991	56.85576099875883
1992	55.47474417994659
1993	55.26793064089879
1994	55.001925057397514
1995	55.146098638142
1996	55.030105209489946
1997	53.09394521529833
1998	51.3778607436175
1999	50.09157150696974
2000	50.43179133900558
2001	51.141594552070735
2002	52.300546119307285
2003	54.58722046538972
2004	53.96741411090315
2005	54.818252388496035
2006	54.945376910481606
2007	54.92846648562971
2008	55.22784830198473