Year	Number
1998	22.3125
1999	22
2000	22.375
2005	23.11111
2007	11.31579
2008	11.30769
2009	9.81081
2010	8.34177
2011	12.45902
2012	11.29258
2013	11.62121
2014	11.25517
2015	11.55686
2016	12.41289
2017	10.78869
2018	11.12435