Year	Number
1996	1.54998731613159
1998	1.52492868900299
2000	1.51018667221069
2002	1.40829694271088
2003	1.53309559822083
2004	1.66827726364136
2005	1.58191788196564
2006	1.54720115661621
2007	1.53769946098328
2008	1.54557907581329
2009	1.55508053302765
2010	1.57483577728271
2011	1.60453939437866
2012	1.64990067481995
2013	1.63109636306763
2014	1.55471169948578
2015	1.546830534935
2016	1.5002669095993
2017	1.52188515663147
2018	1.54260861873627
2019	1.49149036407471
2020	1.49723064899445
2021	1.49592709541321
2022	1.53623878955841