Year	% of total
1990	5.6344754065026565
1991	5.735151582176027
1992	5.760284620903021
1993	5.835552264746919
1994	3.4939279095467635
1995	3.618090744902462
1996	3.799192836703621
1997	3.8575443417217508
1998	3.9339363276595276
1999	4.064262810238202
2000	4.203474545303729
2001	4.27130369525386
2002	4.298193482892865
2003	4.258989343078686
2004	4.295371649658338
2005	4.227433727896806
2006	4.2453808471459995
2007	4.1683579575717244
2008	4.146160668846454