Year	Number
1989	2.9701331597827982
1990	2.869509063029522
1991	2.583521569788394
1992	2.5924794694185604
1993	3.5065429867267413
1994	3.569861102199533
1995	3.206379464818981
1996	1.7327156104495567
1997	1.344549547102774
1998	1.3171415708968075
1999	1.5103858573426958
2000	1.585129457216149
2001	1.3677865395657236
2002	1.4460799707290084
2003	1.4442869751788083
2004	1.3171130900068255
2005	1.721877290303124
2006	1.7480731604298947
2007	1.7037848943088119
2008	2.0004760056131476
2009	1.7840180083107497
2010	1.734363486433592
2011	1.9089595873019205
2012	2.2134280886865687
2013	2.1438905589763215
2014	2.618638122544938
2015	3.2311224303080817
2016	2.8450295336510303
2017	1.8053708613210715
2018	2.228730104450479
2019	1.9459772485105549
2020	2.061763169005995
2021	2.4024996823051867
2022	3.4459229128823914
2023	2.973956293197504