Year	Number
1996	-1.49902832508087
1998	-1.61756873130798
2000	-1.60267579555511
2002	-1.7028511762619
2003	-1.64427065849304
2004	-1.32374036312103
2005	-1.53631925582886
2006	-1.78146910667419
2007	-1.70514690876007
2008	-1.72997355461121
2009	-1.82226276397705
2010	-1.78806269168854
2011	-1.90719747543335
2012	-1.86564028263092
2013	-1.87640869617462
2014	-1.88201534748077
2015	-1.84269392490387
2016	-1.72744107246399
2017	-1.69006109237671
2018	-1.69134342670441
2019	-1.65964019298553
2020	-1.61037731170654
2021	-1.60165119171143
2022	-1.48996067047119