Year	Number
1970	21270
1971	25144
1972	25570
1973	25442
1974	26088
1975	28219
1976	27021
1977	26390
1978	26749
1979	26973
1980	28870
1981	29253
1982	30616
1983	34953
1984	37522
1985	38716
1986	39563
1987	42381
1990	47598
1991	49000
1992	53320
1993	57264
1994	60493
1995	63794
1996	55940
1997	66840
1999	58016
2000	57364
2002	66480
2005	75082
2006	80649
2007	83232
2010	95379
2011	98066
2012	97547
2013	100517
2014	101981
2015	104236
2016	107203
2017	108396
2018	105428
2019	107118