Year	Number
1996	6.91489362716675
1998	6.38297891616821
2000	8.46560859680176
2002	2.64550256729126
2003	1.00502514839172
2004	2.42718458175659
2005	2.91262125968933
2006	3.86473441123962
2007	6.7632851600647
2008	5.76923084259033
2009	5.21327018737793
2010	8.53080558776855
2011	12.3222751617432
2012	8.05687236785889
2013	10.4265403747559
2014	10.9523811340332
2015	12.380952835083
2016	16.1904754638672
2017	18.0952377319336
2018	18.8679237365723
2019	14.6226415634155
2020	21.2264156341553
2021	16.5094337463379
2022	23.1132068634033