Year	% of total
1990	34.02747707301906
1991	33.635726741113494
1992	33.65375795748866
1993	33.572806867518345
1994	33.2813760170945
1995	33.4072336506365
1996	33.61527470180317
1997	33.70871853944122
1998	33.5242519494096
1999	32.99841884326882
2000	32.903039131569
2001	32.955056487224184
2002	32.57504999459822
2003	33.55437630679765
2004	33.26782054154274
2005	33.80188094516868
2006	33.7551111343821
2007	33.8837445893415
2008	35.080929738752744