Year	Number
1976	1.3702633855696675
1977	1.3336498050107193
1978	0.9939509150998815
1979	0.9350800990796136
1980	0.9123325162036707
1981	1.1436177826504683
1982	0.8642003722091307
1983	0.7662976685163745
1984	0.6260472347814018
1985	0.3863304268522496
1986	0.2777288524413786
1987	0.2998403449118242
1988	0.3029770309362028
1989	0.31959378144455125
1990	0.24941511246747453
1991	0.29111850015853247
1992	0.30968987640958917
1993	0.21360264733068596
1994	0.20245891595532498
1995	0.20631419609904342
1996	0.19086255858278228
1997	0.19806534044188281
1998	0.22790967185508346
1999	0.25094085297204677
2000	0.22734969092286691
2001	0.36675793298979886
2002	0.4495877177320616
2003	0.6735149603971421
2004	0.7417968838229975
2005	0.69844955663299
2006	0.5272255461873068
2007	0.537405710301047
2008	0.6301482881129423
2009	0.6216758592849003
2010	0.800088982795132
2011	0.8099621380485555
2012	0.8448085392752132
2013	0.8227695175677598
2014	0.74749404925778
2015	0.8757933147021885
2016	0.9002569617968692
2017	0.9349652414004436
2018	1.1560359528132194
2019	1.2772652342299218
2020	1.585785993676867
2021	1.7707406229888871
2022	1.9020170263296619
2023	1.700510247132666