Year	% of total
1990	9.217484890204235
1991	9.104320322518014
1992	8.675085219777715
1993	9.009442497210154
1994	9.17014606177219
1995	9.481327927765859
1996	9.520233096222878
1997	9.366369545680026
1998	9.162287075054582
1999	8.905620219736065
2000	8.692535204551673
2001	8.497167271756052
2002	8.677171571956338
2003	9.762308406212771
2004	9.008690839019035
2005	9.563636911058667
2006	9.599113420440837
2007	9.144378886883718
2008	8.945111419827105
2009	8.112528248749342
2010	9.604122062540203
2011	10.32670328585025
2012	9.493856200108848
2013	9.916966695022362
2014	10.134492492284695
2015	10.369734519904444
2016	10.371153228976326