Year	Number
2002	18.23337
2003	21.16728
2004	20.55446
2005	20.90935
2006	21.71012
2007	21.54509
2008	19.8478
2009	21.98427
2010	23.65685
2011	24.33038
2012	22.38527
2013	21.86417
2014	21.77518
2015	20.71297
2016	20.3653