Year,Annual mean,5 year mean 2004,2.49,0.56 2005,0.63,1.57 2006,2.56,0.54 2007,0.59,1.56 2008,2.44,0.56 2009,0.57,0.55 2010,2.64,1.54 2011,0.52, 2012,2.52,