Year	Number
1971	11279
1972	14110
1973	16347
1974	18291
1975	20019
1976	23011
1977	24844
1978	30554
1979	32514
1980	38500
1981	45211
1982	54400
1983	55368
1985	58104
1986	59273
1987	50690
1988	46258
1989	45340
1990	49147
1991	50930
1992	43740
2001	70162
2002	71893
2009	93341
2011	126017
2012	125907
2016	118883
2017	137844