Year	% of total
1990	12.199330330711865
1991	11.361478850898896
1992	9.395913290536436
1993	8.048057367260744
1994	7.660443980719924
1995	7.6234783191347955
1996	6.431277321591549
1997	5.975571174299044
1998	6.141846024939298
1999	5.268625970538431
2000	4.4564185474271465
2001	3.9699643573376915
2002	3.713053356619718
2003	3.5468994345213787
2004	2.8996631566793973
2005	2.5646619200188603
2006	2.5748232694087063
2007	2.0835774626211867
2008	1.857979116986046
2009	1.9265097254397234
2010	0.9549014402336232
2011	1.6784741300121002
2012	1.7213621417843974
2013	0.7020888947367682
2014	0.8132478409184213
2015	0.9142319573962058