Year	Number
1960	7.745860629978919
1961	9.007379051236935
1962	8.859328169986899
1963	10.124170752463826
1964	14.498387248952104
1965	12.024574680228486
1966	12.06429280981549
1967	15.165486062013686
1968	14.072989052716368
1969	15.524097336291169
1970	14.758397571922496
1971	5.5206149849987405
1972	10.444474673594723
1973	10.21690727894315
1974	8.785187306636123
1975	11.754634447376604
1976	12.950018944741382
1977	3.593389246410304
1978	5.079816355079272
1979	4.596593975187888
1980	5.473163078068595
1981	8.250616945707117
1982	8.81659729526438
1983	9.564259282614726
1984	11.367549647151177
1985	9.787410472738388
1986	10.112669358533038
1987	10.8384138519179
1988	13.502934542919192
1989	18.270762899147297
1990	21.526081344743595
1991	19.308627461661963
1992	15.5462391368242
1993	13.548554574733402
1994	13.616462828904979
1995	16.522571981839334
1996	19.682867391653406
1997	32.14544163176622
1998	38.11506004744489
1999	32.677663754199706
2000	30.776832502521884
2001	34.22986296034575
2002	32.28556528164777
2003	37.661825188064846
2004	42.060694125101804
2005	49.970069291177076
2006	53.45808035479191
2007	55.28944191187197
2008	71.78367764702884
2009	49.572468467551836
2010	41.442799975930456
2011	36.69146944102835
2012	34.14407984188179
2013	34.03855806704375
2014	33.30968507953129
2015	26.5078579366292
2016	27.956011369297094
2017	25.81175125554183
2018	24.616708755709176
2019	23.109392250909995
2020	24.547343273062037
2021	26.795214357738743
2022	28.707301214770112
2023	27.947393161872427