Year	Number
1971	5042
1972	5482
1973	5791
1974	5997
1975	6162
1976	6618
1977	7456
1978	7588
1979	8101
1980	8940
1981	9657
1982	10569
1983	12424
1984	14430
1985	15913
1986	15918
1987	15978
1988	16136
1989	17310
1990	18510
1991	20400
1992	21786
1993	25929
1994	27120
1995	31567
1996	32097
2008	116924
2009	123022
2010	124397
2021	369783