Year % 2002 9.54150323596095 2003 9.83931168042677 2004 10.1667218457432 2005 10.1503557634588 2006 9.517944993933 2007 10.9938508263563 2008 9.3702598365416 2009 7.58063046634046 2010 8.64764011395425 2011 8.23675339049387 2012 7.67463613213552 2013 6.57881884807328 2014 5.48951502356822 2015 4.22619645319521 2016 3.53340793326882 2017 3.67960022595704 2018 3.83711503544425 2019 5.17518323954627