Year	% of total
1990	44.13009447443589
1991	44.391057476716995
1992	44.97346746745311
1993	44.945029375930396
1994	45.53180086174114
1995	45.883044564169516
1996	45.379300024109874
1997	44.45108755607795
1998	44.43266496991993
1999	44.07546988739134
2000	43.559281276102986
2001	43.161777130392174
2002	43.10233430417282
2003	42.248556881378654
2004	42.05977072534531
2005	41.95183062327261
2006	40.851101848013094
2007	39.658823386437795
2008	38.841950553333234