Year	Number
1996	2.0205249786377
1998	1.97490954399109
2000	1.8057245016098
2002	1.70812404155731
2003	1.64780592918396
2004	1.7263457775116
2005	1.61318349838257
2006	1.83990871906281
2007	1.86806631088257
2008	1.78526794910431
2009	1.58159780502319
2010	1.73051977157593
2011	1.64937400817871
2012	1.63784003257751
2013	1.7610878944397
2014	1.81952893733978
2015	1.83466100692749
2016	1.74932622909546
2017	1.70492851734161
2018	1.76942324638367
2019	1.61285722255707
2020	1.47402393817902
2021	1.45237493515015
2022	1.5665100812912