Year	Number
1960	1.295775663206459
1961	1.3753702920016928
1962	1.3154108603609158
1963	1.290095525389643
1964	2.2578815652002664
1965	1.8267907869861724
1966	2.160364145658263
1967	2.739845025886931
1968	1.703808796245771
1969	1.5535027570350173
1970	1.319125211060034
1971	1.5051731479826251
1972	1.5187562045009222
1973	1.686921352306358
1974	1.8103603610018386
1975	3.5663108951785194
1976	3.990056104698373
1977	3.5587872056975374
1978	4.922630224676764
1979	4.3460644748277515
1980	8.116713352007471
1981	14.477233136511215
1982	40.17946880880312
1983	18.083306841070254
1984	36.43955814902594
1985	21.99734521183475
1986	10.397399453679668
1987	17.393592150757403
1988	24.34376410742429
1989	45.945045058577826
1990	21.67316676224814
1991	11.042513777884869
1992	4.426287594427886
1993	3.102885631281351
1994	2.3275743504758744
1995	2.539162217513529
1996	3.5152397198198293
1997	3.3542269359989687
1998	2.0546798042755507
1999	2.7261837556778614
2000	2.113768630596425
2001	2.801734673557131
2002	2.073520756830656
2003	2.875597049084084
2004	1.5991075377998065
2005	1.4384717599797958
2006	1.5827332937084797
2007	1.5619854187563564
2008	1.946483861060512
2009	1.2537191073961846
2010	1.3117634186447473
2011	1.4485125698669312
2012	1.6252398761377167
2013	1.6187986696620258
2014	1.702749964981075
2015	0.001759828864415494
2016	0.0019491232971894873
2017	0.0016084817652318262
2018	0.001877752941296535
2019	0.0017863991612116277
2020	0.001694907144776714
2021	0.0014573618562798885
2022	0.002325221950184192
2023	0.0025656973889113194