Year	Number
1971	45827
1972	49197
1973	51307
1974	53858
1975	55878
1976	57522
1977	53750
1978	50996
1979	51018
1980	49497
1981	43572
1982	42148
1983	40684
1984	40724
1985	39892
1986	42531
1990	70999
1992	83674
1993	81782
1996	71403
1998	67557
1999	47393
2000	53146
2001	52644
2002	58720
2003	53063
2004	54757
2005	63290
2006	55264
2007	58127
2008	71546
2010	82111
2011	85158
2012	81095
2013	95817
2014	90228
2015	83324
2016	78791
2017	72584