Year	Number
1996	1.99304711818695
1998	2.07239747047424
2000	2.10799384117126
2002	1.79351305961609
2003	1.92824709415436
2004	2.0158543586731
2005	1.99800038337708
2006	2.24886965751648
2007	2.40786051750183
2008	2.46965980529785
2009	2.30715298652649
2010	2.28112554550171
2011	2.19381713867188
2012	2.20258617401123
2013	2.12852215766907
2014	2.21809077262878
2015	2.24877071380615
2016	2.21457314491272
2017	2.22528839111328
2018	2.23167037963867
2019	2.23171925544739
2020	2.28457260131836
2021	2.25011277198792
2022	2.14482593536377