Year	% of total
1990	90.28743057364157
1991	89.94499674498451
1992	89.74608342551952
1993	89.34736444635618
1994	89.15375232030534
1995	88.87262346789186
1996	89.09116200043115
1997	88.74950697309616
1998	88.3054492262642
1999	88.54182911583922
2000	88.6348259601621
2001	89.16325050457435
2002	88.60015456218608
2003	85.63452382038484
2004	85.6242615129935
2005	85.90976441181614
2006	87.09554421805333
2007	84.8452508122781
2008	87.26381692940737