Year	Number
1960	9.284346375961402
1961	6.578182117271117
1962	6.895823263912072
1963	5.617365607367837
1964	6.057260959118202
1965	7.759794010930966
1966	8.340748797011587
1967	10.447227961756228
1968	10.227701093214566
1969	13.244786030512449
1970	10.289376081191055
1971	5.691927176919805
1972	3.7635492544476383
1973	5.108556804850069
1974	7.479750282445433
1975	11.159463586441994
1976	11.94280036327919
1977	13.393900061101375
1978	12.636347399620785
1979	9.897110468520582
1980	9.537289835812631
1981	14.411544876584852
1982	7.310695697717222
1983	5.854514674490039
1984	7.67553685177715
1985	9.064343431442433
1986	7.3187108618871335
1987	6.604989424779106
1988	6.394025566966964
1989	9.315295259382658
1990	8.715210543537411
1991	8.984227116556898
1992	13.197523649504237
1993	12.446324369829057
1994	13.357437233456391
1995	14.89296120214942
1996	14.468017388358236
1997	15.844681930021341
1998	17.03129918364794
1999	12.310128822349006
2000	14.929654094298593
2001	14.271739717948872
2002	12.888808000612388
2003	10.491030790333904
2004	12.858541958394952
2005	12.585966839003998
2006	11.327970396754075
2007	28.74772430133177
2008	31.348187290778302
2009	20.98589370746635
2010	27.30475609480284
2011	29.858653750440283
2012	31.86966363819464
2013	31.477098732562716
2014	29.548051027156433
2015	33.6963347969531
2016	27.207509168987432
2017	23.55179813177127
2018	30.17890336588842
2019	29.523676147870727
2020	42.87743043667604
2021	37.442200316911325
2022	40.06911886133948
2023	35.49838133870351