Year	% of total
1990	71.32121897225755
1991	69.64150942279942
1992	65.2112303137277
1993	57.72791178616554
1994	44.04012530012788
1995	41.0273522872671
1996	39.37050941582548
1997	44.52407975675031
1998	45.003656402970265
1999	41.45829331165089
2000	38.52974548812238
2001	36.92339030234788
2002	35.52144568844031
2003	35.167746601526176
2004	38.763436572213834
2005	36.72646903098461
2006	38.30304763444136
2007	42.587063210403535
2008	41.55518769464502
2009	35.642351519903805
2010	34.60580973884254
2011	36.25452584123022
2012	42.33052237756576
2013	33.940338730232575
2014	45.98414186255212