Year	Number
1971	26668
1972	27391
1973	36155
1977	37255
1978	47877
1979	67416
1980	92815
1981	90041
1982	89835
1983	105395
1985	135068
1986	140015
1987	103322
1990	145341
1991	148409
1992	145398
1993	147201
1994	150683
1995	165868
1998	73573
1999	82574
2000	103763
2001	121673
2002	158076
2004	219922
2005	280590
2006	341693
2007	416193
2008	482779
2009	561099
2010	636740
2011	682113
2012	695564
2013	960743
2014	973415
2015	1020695
2016	1061181
2017	1103887
2018	1196538