Year	% of total
1992	36.858347222916194
1993	39.15062589235799
1994	40.86456573831891
1995	41.36190240195486
1996	43.52246331488677
1997	44.633696884319
1998	44.549982788271926
1999	45.45636580231184
2000	45.03134994606583
2001	46.25881390396907
2002	45.695417257688376
2003	46.96404478089367
2004	47.6329306944916
2005	48.36946179255716
2006	46.15430132384759
2007	46.72670028142968
2008	46.061222709726465
2009	46.13480039263513
2010	48.286401959852476
2011	47.24084435459855
2012	46.12335544255223
2013	46.35991723977992
2014	47.64114332874105
2015	46.38073260013773
2016	46.12364228418548