Year	% of total
1990	9.845280701084446
1991	9.673412756137392
1992	9.489712976407297
1993	9.652068007770074
1994	9.291875947217694
1995	8.530803112653388
1996	8.142903667010161
1997	8.68169376622888
1998	8.572343686883286
1999	8.377184844175844
2000	8.632648586325132
2001	8.688718305977773
2002	8.424867591349791
2003	8.384604924546947
2004	8.206754688349724
2005	8.169190495821667
2006	8.22608044687519
2007	8.258258083351656
2008	8.303930214465705