Year	% of total
1990	15.051864930478922
1991	8.254110278492337
1992	15.356099752864525
1993	19.02969468841489
1994	20.893650974581103
1995	9.51918930573523
1996	11.71574330976461
1997	11.438898114682036
1998	11.681508643268728
1999	9.509131540417663
2000	13.948326378407176
2001	14.24320726646308
2002	19.889807162534435
2003	15.62310491206792
2004	17.694466431603946
2005	13.892930994868651
2006	15.925094792230906
2007	24.424073335990435
2008	19.23949612706361
2009	16.537023186237846
2010	17.254663422546635
2011	23.310209889718962
2012	23.704333050127442
2013	14.490571449057143
2014	7.457576659720155
2015	10.651361452215696