Year	Number
1971	154605
1972	158341
1973	164111
1974	158788
1975	170488
1976	136483
1977	113357
1978	90512
1979	46625
1980	43732
1986	7551
1987	10136
1988	16424
1990	17014
1991	32274
1992	31356
1993	78834
1994	111554
1995	116319
1996	126004
1998	111974
1999	102343
2000	98490
2001	114438
2002	114920
2003	105753
2004	93552
2005	110303
2006	110647
2007	124721
2008	153204
2009	177350
2010	183156
2011	182926
2012	184953
2013	219620
2014	213205
2015	220261
2016	197748
2017	192356