Year	% of total
1990	11.243988773023064
1991	11.595706629339817
1992	11.989152371418161
1993	12.22797045031577
1994	9.705722075428394
1995	9.468660915235523
1996	9.298774601441883
1997	8.985329841706701
1998	8.301319278407998
1999	7.770704270291944
2000	7.259987642485578
2001	7.338721376106307
2002	7.015025385427181
2003	7.157004892040796
2004	7.197223369463074
2005	7.072794876224728
2006	7.5150569416647395
2007	7.648497889693914
2008	7.873991577300523