Year	Number
2002	20.45743
2004	24.3252
2007	19.33686
2009	20.79199
2010	21.56648
2011	23.37541
2012	22.516
2013	22.94237
2014	21.90267
2015	25.93847
2016	26.03456
2017	25.05716
2018	24.95251