Year	% of total
1990	16.406099208646978
1991	28.058007566204285
1992	22.87872056863616
1993	23.12946783161239
1994	26.652527394839165
1995	52.382664988311454
1996	35.25909237206308
1997	49.97512025211478
1998	49.50734937812955
1999	42.662235438166874
2000	45.18294729775093
2001	48.56396866840731
2002	28.610255481065412
2003	27.649518269405565
2004	30.36484245439469
2005	28.937786924172865
2006	24.844302306009087
2007	25.24584604950831
2008	26.16984402079723
2009	20.34914477164521
2010	22.153751348020336
2011	32.16689098250337
2012	42.29716276754604
2013	41.15434500648508
2014	42.438709677419354
2015	35.91486087959995