Year	% of total
1990	11.322575757562289
1991	11.537090097285253
1992	12.123084075609052
1993	13.051000348165678
1994	12.33090526164707
1995	12.920372923579412
1996	14.575127375313022
1997	14.610312819135823
1998	14.128892111898844
1999	14.826298050042992
2000	15.463498160867603
2001	15.676578188546728
2002	16.079761976834618
2003	16.057479736879603
2004	15.614458653938234
2005	15.759867106891273
2006	15.609734001407688
2007	15.368581161913653
2008	15.119353633580717
2009	15.403950170239824
2010	15.265043421585723
2011	15.134885398120392
2012	15.069659079463399
2013	14.335466599828765
2014	15.079958748566638
2015	0