Year	% of total
1990	48.92433963583946
1991	49.20089618574063
1992	42.9191654254804
1993	46.21346188204958
1994	44.805607330004285
1995	44.75252008804831
1996	46.04434516349229
1997	47.922927158038185
1998	50.340163481392324
1999	46.62768013405749
2000	48.13278676932965
2001	52.310939859364986
2002	48.84494660588571
2003	47.8058169707531
2004	41.85563244005736
2005	40.67789603889727
2006	43.221513286708074
2007	40.40500896914596
2008	40.306333785320994
2009	36.026366251678624
2010	37.06130038722885
2011	32.972029998635286
2012	29.23980254416905
2013	31.740070256960866
2014	27.006803939838512
2015	26.60300596666984
2016	27.67410388113079