Year	Number
1996	1.57104122638702
1998	1.54939877986908
2000	1.60359740257263
2002	1.87359666824341
2003	1.7044905424118
2004	1.81070196628571
2005	1.53672695159912
2006	1.34489262104034
2007	1.37706923484802
2008	1.43763339519501
2009	1.28647637367249
2010	1.26525807380676
2011	1.26211905479431
2012	1.40279400348663
2013	1.305992603302
2014	1.37168157100677
2015	1.35833406448364
2016	1.33147585391998
2017	1.34039711952209
2018	1.29267823696136
2019	1.18073284626007
2020	1.03821742534637
2021	1.01972794532776
2022	1.10425877571106