Year Number 1996 2.19 1997 1.8 1998 1.75 1999 1.2 2000 1.04 2001 2.79 2002 1.92 2003 5.4 2004 4.18 2005 4.69 2006 12.48 2007 21.24 2008 23.41 2009 17.53 2010 17.49 2011 23.02 2012 29.85 2013 34.5 2014 55.26 2015 33.62 2016 34.97 2017 55.14 2018 45.86 2019 57.54 2020 56.11