Year	Number
1996	1.72499644756317
1998	1.94985711574554
2000	2.02971863746643
2002	2.09640264511108
2003	2.19400310516357
2004	2.14761972427368
2005	2.12453174591064
2006	2.1676173210144
2007	1.96812081336975
2008	2.04124021530151
2009	2.22546005249023
2010	2.22388696670532
2011	2.23519229888916
2012	2.2103111743927
2013	2.18119192123413
2014	2.02586197853088
2015	1.84421217441559
2016	1.84277081489563
2017	1.97704017162323
2018	2.0138726234436
2019	1.97287130355835
2020	1.90141117572784
2021	1.92068529129028
2022	1.75512683391571