Year	% of total
1990	47.6836168428046
1995	45.6451980003177
2000	46.3601663987974
2005	27.9585646244447
2010	40.7201630871343
2011	36.4794676899234
2012	28.8448650385155
2013	27.5109097722025
2014	10.0439638680912
2015	13.5577134646425
2016	8.11560836990258
2017	8.24649365056527