Year	Number
2004	0.42519822716713
2005	0.443682581186295
2006	0.423959523439407
2007	0.382787048816681
2008	0.383233666419983
2009	0.370833456516266
2010	0.39340415596962
2011	0.411335080862045
2012	0.34492501616478
2013	0.393689393997192
2014	0.29147407412529
2015	0.304494768381119
2016	0.316129863262177
2017	0.344771087169647
2018	0.314446359872818
2019	0.315212190151215
2020	0.320048034191132
2021	0.336863189935684
2022	0.393693715333939