Year	Number
1996	22.6130657196045
1998	18.5
2000	15.9203977584839
2002	23.8805961608887
2003	24.8756217956543
2004	24.519229888916
2005	25.8373203277588
2006	24.8803825378418
2007	26.7942581176758
2008	27.4038467407227
2009	25.5924167633057
2010	23.6966819763184
2011	23.0046939849854
2012	24.4131450653076
2013	22.5352115631104
2014	20.6730766296387
2015	20
2016	20
2017	23.3333339691162
2018	23.8095245361328
2019	24.761905670166
2020	25.238094329834
2021	25.7142848968506
2022	18.8679237365723