Year	% of total
1991	42.858330417264945
1992	42.338250858606315
1993	43.72532741720224
1994	43.19742721876856
1995	43.38444509886694
1996	43.25955130161431
1997	43.68665738152078
1998	44.714579756077434
1999	44.46457947913888
2000	43.24569402153054
2001	44.2066276061594
2002	44.008786720557396
2003	42.7701903456473
2004	42.53390747641459
2005	42.411572176519115
2006	42.018813308159885
2007	41.002288164114006
2008	41.83646311539729
2009	42.76371145136037
2010	41.05393753113084
2011	40.87261600543014
2012	39.69913179176843
2013	39.85414840429046
2014	41.45134176763949
2015	38.28278854962091
2016	38.93353308940908