Year	% of total
1990	41.785593310988986
1991	41.25124855614438
1992	41.536822165917044
1993	41.48160645262207
1994	41.32893770028499
1995	40.917870069162284
1996	40.752408783528736
1997	39.88652236592036
1998	40.48467797068649
1999	40.8672895574838
2000	40.51845734243
2001	40.911302924342166
2002	41.31678567899817
2003	42.245120162502424
2004	42.71779229930603
2005	42.79877909563272
2006	42.89323224247561
2007	41.86472877674511
2008	40.897292198931304
2009	42.39335060067194
2010	40.7783885045088
2011	40.84979428464127
2012	41.5454250150706
2013	41.00487417169649
2014	41.146336572507295
2015	43.34182237134261
2016	43.751820868000905