Year	Number
1960	4.651456173901807
1961	5.596861562483468
1962	5.92317949080969
1963	6.054654931693784
1964	8.903978970078116
1965	10.992783811940356
1966	14.713093944189971
1967	19.137746566882317
1968	13.783341554852447
1969	11.719299555240095
1970	22.402006430275907
1971	24.976980750064907
1972	14.749901352229164
1973	5.057197159052465
1974	4.574753490277808
1975	6.781478037947419
1976	7.377435501763678
1977	8.31777976638695
1978	8.963324614776361
1979	7.426893819040657
1980	6.270344243206701
1981	7.533305746624314
1982	6.914190022898709
1983	4.692436344098253
1984	7.7094994656633355
1985	8.859381867427468
1986	9.431146885112502
1987	10.488313648257188
1988	13.343245113578133
1989	12.02466482973781
1990	14.964143435325806
1991	14.602992653758474
1992	13.644034597003145
1993	11.778547916072354
1994	6.390668137652678
1995	10.452695980858792
1996	22.29769365165686
1997	16.770499207319595
1998	18.037817952170833
1999	13.329615419551043
2000	13.67484643538249
2001	6.880716836075874
2002	3.6692640081488417
2003	3.3847125510260363
2004	4.513372071205195
2005	4.9147842437764115
2006	6.008523690904372
2007	5.678286810899826
2008	10.265651034889835
2009	6.380269403758041
2010	5.391573364097991
2011	5.804959282997804
2012	8.438867773528454
2013	15.786888921958623
2014	8.852137430054212
2015	7.2033071794559795
2016	7.233539659057686
2017	9.44836970775528
2018	15.410816706508697
2019	9.903081810356467
2020	8.844270982554821
2021	7.831916927895142
2022	17.418812803667148
2023	10.477162259088862