Year	Number
1996	1.95973467826843
1998	1.96349668502808
2000	1.89046895503998
2002	1.97525644302368
2003	1.85602164268494
2004	1.87731623649597
2005	1.77208602428436
2006	1.56682622432709
2007	1.5860413312912
2008	1.61668634414673
2009	1.74351441860199
2010	1.71641802787781
2011	1.74265909194946
2012	1.66362190246582
2013	1.62291133403778
2014	1.64855718612671
2015	1.69271349906921
2016	1.65607154369354
2017	1.64494383335114
2018	1.73642694950104
2019	1.69563114643097
2020	1.79281723499298
2021	1.67903685569763
2022	1.77271509170532