Year	Number
1970	409.0561
1971	424
1972	241
1973	293
1974	0
1975	0
1976	0
1977	0
1978	0
1979	184
1980	227
1981	203.1656
1982	182.498
1983	165.0006
1984	150.2747
1985	138.506
1986	128.4719
1987	118.1837
1988	107.109
1989	95.86287
1990	84.43114
1991	73.32249
1992	63.34443
1993	54.64067
1994	46.81523
1995	39.67733
1996	32.94736
1997	26.36454
1998	7299.185
1999	14258.41
2000	21433.44
2001	28660.29
2002	36081.86
2003	43607.09
2004	51242.67
2005	59010.02
2006	67164.61
2007	75332.9
2008	83203.41
2009	90420.3
2010	96248.5
2011	102547.7
2012	116287
2013	119479
2014	123454
2015	123324
2016	125029
2017	128399
2018	128050.6