Year	Number
1971	9786
1972	11343
1973	12622
1974	17831
1982	40027
1983	32004
1984	33521
1985	29191
1986	31161
1987	30310
1988	31658
1989	31953
1991	31062
1992	36402
1998	32144
2007	86769
2010	93734
2011	118158
2015	112352
2016	95827
2017	103562
2018	88563