Year	Number
2002	22.815
2003	23.0603
2004	24.89589
2005	24.57527
2006	23.15217
2007	23.08621
2008	21.77823
2009	21.57417
2010	21.38246
2011	18.59375
2012	23.42684
2013	22.62949
2014	20.6272
2015	20.43346
2016	22.67354
2017	22.61795
2018	22.98876