Year	Number
2003	22.41195
2004	23.19856
2005	23.81989
2006	22.33487
2007	21.54925
2008	20.28997
2009	22.71423
2010	21.25288
2011	17.69454
2012	20.51162
2013	19.89231
2014	18.72044
2015	18.28032
2016	19.23231