Year	Number
1960	1.426235258919022
1961	1.7523302268003174
1962	2.1422036845714763
1963	1.5524260420524123
1964	1.8572392602257077
1965	2.3506016727841583
1966	1.8295981050007877
1967	1.7076567842410821
1968	1.4176411971199387
1969	1.6674058929028204
1970	1.774061883414069
1971	1.4571758025012858
1972	1.2271585771076532
1973	0.8210233574728949
1974	0.5719036033565332
1975	0.9795191363628009
1976	0.7501627682698128
2004	1.2494416830617434
2005	0.8308004114198563
2006	0.6770709319499228
2007	0.6920745063885438
2008	0.6178067235308987
2009	0.9020748831952993
2010	1.03655668650065
2011	1.037660402532172
2012	0.9411678314260054
2013	0.987411074659388
2014	1.2032035333086917
2015	1.341134683912769
2016	1.6910359756737716
2017	1.5903050313150742
2018	1.2461736582326213
2019	1.2866314886158277
2020	1.8480369585746521
2021	1.501970307820958