Year	Number
1991	12.16979265035111
1992	6.370714654846119
1993	8.127559312056501
1994	5.532940183730101
1995	5.35728302385563
1996	8.56904768050006
1997	1.4228250388296568
1998	1.2351424379132099
1999	1.2560434545344816
2000	1.3236135240636653
2001	1.5585759684703087
2002	1.3856479080585564
2003	1.4175994443918616
2004	1.4136841116430106
2005	1.8450680400354358
2006	1.7490504976437313
2007	1.678903676041566
2008	1.9111580223407203
2009	1.8319653624847403
2010	1.9969370630341985
2011	2.353133231746324
2012	1.977121638303525
2013	2.2961723427715723
2014	2.294798522713139
2015	1.894102002007007
2016	1.789287212770509
2017	1.745010022716623
2018	1.9612168220612376
2019	2.1020351442053755
2020	1.7526622803408618
2021	1.940860520490917
2022	1.8700574151255565
2023	1.8465788852096694