Year	number
2005	14.65
2006	14.85
2007	14.8
2008	14.9
2009	14.8
2010	15.05
2011	15.05
2012	14.85
2013	15.19409090909091
2014	15.330454545454547
2015	15.421363636363639
2016	15.466818181818184
2017	15.466818181818184
2018	15.375909090909092
2019	15.19409090909091