Year	Number
1971	6745
1972	7297
1973	8645
1974	7729
1975	9253
1976	17095
1977	17961
1978	21814
1979	24366
1980	24968
1981	23750
1983	24302
1984	21545
1985	21758
1987	27086
1999	25699
2014	96805
2015	108384
2016	105353
2017	107060
2018	116644