Year	Number
1996	1.14636123180389
1998	1.25856113433838
2000	1.29082238674164
2002	1.40098106861115
2003	1.41872799396515
2004	1.38215363025665
2005	1.3669136762619
2006	1.07571339607239
2007	1.25134766101837
2008	1.18566608428955
2009	0.790569603443146
2010	0.716390430927277
2011	0.610664069652557
2012	0.61443954706192
2013	0.632410943508148
2014	0.664432346820831
2015	0.569784104824066
2016	0.234157800674438
2017	0.163212507963181
2018	0.0695338472723961
2019	0.0461379736661911
2020	0.0232638418674469
2021	0.0704413056373596
2022	0.133635863661766