Year	% of total
1990	57.81503426611457
1991	56.010411890813195
1992	48.45855952365352
1993	48.89075060257245
1994	50.34793594124826
1995	50.160317593443395
1996	51.11953701800611
1997	49.21832379432704
1998	46.467122268589236
1999	46.32791130065061
2000	45.198769593611665
2001	44.28798026502421
2002	46.14731013325479
2003	48.46876884820886
2004	49.56313720919612
2005	51.20681247582139
2006	52.365305304160636
2007	50.49021374867757
2008	54.95224243567003
2009	52.38757861510315
2010	54.54716029085705
2011	56.33633387772735
2012	56.68155736078386
2013	54.41362938308017
2014	54.182942800322394
2015	54.13213193857116
2016	52.872027639848305