Year	Number
1960	5.772164721785332
1961	8.972748068258854
1962	6.433502089931263
1963	7.767633959999007
1964	6.844968685020636
1965	7.3004190432307885
1966	7.376619053008634
1967	5.769035749853906
1968	6.592799939815345
1969	5.711726174544607
1970	5.073113854401061
1971	3.180570853018112
1972	2.696382211868338
1973	3.286328221441608
1974	5.625722184176128
1975	7.627838937693598
1976	6.778283352284656
1977	8.650895744852502
1978	11.027829664090175
1979	12.31560594887869
1980	16.813488532430377
1981	9.03262566183651
1982	9.52312333805488
1983	7.529234758404708
1984	3.1338251862255753
1985	4.5856477102946585
1986	2.5082885221600018
1987	3.9964651301678606
1988	9.987766452927081
1989	9.435798498780796
1990	7.6999752998020305
1991	10.31146406743358
1992	9.702406513791134
1993	9.888082235956565
1994	10.719026671414515
1995	10.72743009259652
1996	9.472400717425227
1997	12.27443486914042
1998	10.8832388248156
1999	10.847687923486182
2000	10.503310958088111
2001	12.107144547217523
2002	10.264662543827853
2003	11.35798100129692
2004	11.33773998038734
2005	10.156729994915295
2006	6.579257432459327
2007	6.75980182018703
2008	11.13344664007136
2009	6.96804175921466
2010	8.121861471865431
2013	10.859074377001157
2014	12.05949181972326
2015	12.015810957144586
2016	10.659312671072355
2017	10.051361930036327
2018	12.202939414036937
2019	12.059439086859589
2020	17.27207596207474
2021	17.189380670582207
2022	17.559016792337065
2023	16.37746137685761