Year	Number
1970	24365
1971	26273
1972	30812
1973	33774
1974	35868
1975	41391
1976	43004
1977	43246
1978	42950
1979	45041
1981	49334
1982	50353
1984	55731
1986	58226
1987	63391
1988	65582
1989	67007
1990	65643
1991	68506
1992	69596
1993	77665
1994	83252
1995	78759
1998	132635
2012	378365
2018	517732