2003
2004
2005
2006
2007
2008
2009
2010
2011
2012

2003-2012 combined

Spring 2003

First confirmed arrival date: 8 April 2003

Spring 2004

First confirmed arrival date: 9 April 2004

Spring 2005

 First confirmed arrival date: 14 April 2005

Spring 2006

 First confirmed arrival date: 15 April 2006

 Spring 2007

First confirmed arrival date: 13 April 2007

Spring 2008

First confirmed arrival date: 10 April 2008

Spring 2009

First confirmed arrival date: 2 April 2009

Spring 2010

First confirmed arrival date: 1 April 2010

Spring 2011

First confirmed arrival date: 9 April 2011

Spring 2012

First confirmed arrival date: 17 March 2012 (plus 6 other confirmed March reports!)

2003-2012 Combined

First confirmed arrival date: 17 March 2012