Year	Number
1971	5142
1972	5599
1975	5993
1976	6373
1977	6790
1978	7088
1980	9056
1981	9528
1982	10025
1983	10451
1984	11311
1985	12215
1986	10837
1988	13640
1989	13120
1990	11280
1991	10850
2001	14875
2011	38125
2012	37957
2013	37317
2015	40303
2016	37837
2017	37703
2018	49768
2019	47738
2020	46677
2021	43747