Year	number
2005	13.8
2006	13.8
2007	13.8
2008	13.8
2009	14
2010	14.2
2011	14.2
2012	14
2013	17.0725
2014	16.8225
2015	17.028750000000002
2016	17.278750000000002
2017	16.985
2018	15.264999999999999
2019	14.57375