Year	% of total
1990	46.41595355021418
1991	45.05273576662289
1992	45.424691094726924
1993	45.62660925652787
1994	45.61032055193447
1995	45.14127296108602
1996	44.823940023378356
1997	44.256787845567715
1998	44.4027056554281
1999	44.59649110905198
2000	43.67846747184168
2001	43.75356101366654
2002	43.816196197529315
2003	43.83627963852676
2004	43.741197996959066
2005	43.7030368948808
2006	43.22514281445072
2007	42.122893194724305
2008	41.84074770292981
2009	42.45510329632867
2010	40.82624422828209
2011	40.705132719174756
2012	40.80364257487949
2013	40.34027362427032
2014	40.68965921489403
2015	41.01286549400737
2016	41.26982441365289