Year	% of total
1990	4.787217335118029
1991	4.562705759975398
1992	4.414522567726413
1993	4.321441877330451
1994	4.5880399105697665
1995	4.473105411437224
1996	4.450252186381335
1997	4.408637573134161
1998	4.380180536264648
1999	5.40130772718536
2000	5.405498825547212
2001	5.360337449739874
2002	5.432221254753682
2003	5.340366152456312
2004	6.2308350869035785
2005	6.1803363496891395
2006	5.717649068549624
2007	5.569660049425883
2008	5.116874302859046