Year	% of total
1990	20.89939857845817
1991	37.27239753355096
1992	52.22988505747126
1993	71.14517583408477
1994	81.50329877474081
1995	82.7766416723472
1996	70.24523160762944
1997	53.10895607529949
1998	50.20381183210312
1999	54.48099271223163
2000	48.84456803145076
2001	48.70276367738297
2002	48.845618915159946
2003	39.95206816971418
2004	46.975172847265874
2005	47.59561974289795
2006	44.007814261026375
2007	33.952817379497624
2008	32.83410915469203
2009	39.82001531784529
2010	46.86989021256716
2011	28.71073298429319
2012	29.931827865360034
2013	41.464672511603915
2014	36.726485148514854
2015	35.51730756926227