1995,8.348685,
1996,7.263224,
1997,7.604521,
1998,9.673973,
1999,9.434603,
2000,8.834836,
2001,8.448822,
2002,9.267753,
2003,7.855562,
2004,8.468033,
2005,9.42063,
2006,9.279096,
2007,8.981781,
2008,8.548497,
2009,8.226247,
2010,9.612219,
2011,8.931288,
2012,10.31932,
2013,9.103753,
2014,7.708055,
2015,8.688466,
2016,10.28967,
2017,9.577397,