Year	% of total
1990	54.980216135416505
1991	53.6314288806124
1992	53.64982155412276
1993	52.526454268244706
1994	52.319222762126195
1995	51.788169176319485
1996	51.145719864130314
1997	50.759483969293406
1998	50.38028756188129
1999	50.499922012490345
2000	49.49248776866599
2001	49.714340295882714
2002	49.71090889509766
2003	49.40317595847907
2004	49.4368928155905
2005	49.50893547929156
2006	49.64755163782488
2007	49.91727087400234
2008	49.773191485229496