Year	Number
1971	17368
1972	18184
1973	18715
1974	20007
1978	29709
1979	31418
1980	33992
1982	41414
1983	45082
1984	46578
1986	49601
1987	54279
1988	53630
1989	55651
1990	59110
1991	61696
1992	66399
1993	70156
1994	74635
1995	82003
1997	90388
2012	203832
2013	253399
2014	276319
2015	298125
2016	334845
2017	347092
2018	369013
2019	395146
2020	410454
2021	413177