Year	Number
1976	77723
1978	99444
1979	113981
1980	126529
1981	133086
1982	121240
1983	118293
1984	123748
1985	123797
1986	135546
1987	133552
1988	135051
1989	135207
1990	139822
1991	138185
1994	30032
1995	20614
1998	15560
1999	15133
2000	14501
2001	16387
2002	18495
2003	20291
2004	24029
2006	29249
2007	30151
2008	29652
2009	21658
2010	20006
2011	18697
2012	19180
2013	24288
2014	26681
2015	22801
2016	21424
2017	20981
2018	20605