Year	Number
1996	1.92331528663635
1998	1.94982421398163
2000	1.83087551593781
2002	1.84875297546387
2003	1.88110423088074
2004	1.96196269989014
2005	1.91248178482056
2006	1.96577215194702
2007	1.92829203605652
2008	1.95778656005859
2009	1.87349915504456
2010	1.88987576961517
2011	1.86417806148529
2012	1.95103108882904
2013	1.97093689441681
2014	2.02437782287598
2015	1.97531950473785
2016	1.99505138397217
2017	1.98009264469147
2018	1.92218768596649
2019	1.94109773635864
2020	1.9314512014389
2021	1.90818059444427
2022	1.76217150688171