Year	Number
1996	1.38243699073792
1998	1.3557049036026
2000	1.4082487821579
2002	1.27081513404846
2003	1.27646601200104
2004	1.47755229473114
2005	1.62385451793671
2006	1.39654088020325
2007	1.39714181423187
2008	1.42259049415588
2009	1.35357344150543
2010	1.32443165779114
2011	1.3053605556488
2012	1.32252132892609
2013	1.31173515319824
2014	1.31752860546112
2015	1.33469295501709
2016	1.29103517532349
2017	1.29456353187561
2018	1.29546582698822
2019	1.30319917201996
2020	1.38950836658478
2021	1.41824901103973
2022	1.44950783252716