Year	% of total
1990	32.94905150327459
1991	32.828778821898155
1992	32.688735295303644
1993	32.16615379463368
1994	31.652953229887242
1995	31.67457102018822
1996	32.00255792890507
1997	32.137918996077936
1998	31.980763948688026
1999	31.36752715431324
2000	31.135783693870806
2001	30.900545138851907
2002	30.39141378412421
2003	31.115524444406017
2004	30.642922204656124
2005	30.997708274412464
2006	30.92979688516412
2007	31.280283425609717
2008	32.81732337334806