Year	Number
1971	7025
1972	7153
1973	7586
1974	7777
1975	7854
1976	8022
1977	8161
1978	8131
1979	8508
1980	10002
1981	11912
1982	13043
1983	13590
1984	14105
1985	14394
1986	14896
1987	16003
1988	16975
1989	17921
1990	18524
1991	19183
1992	18937
1997	20232
1998	22435
1999	23730
2000	26499
2001	28698
2002	26024
2003	27319
2004	28254
2005	26944
2006	30637
2007	31037
2008	32338
2009	33158
2010	35583
2011	40299
2012	40397
2013	40159
2014	41193
2015	42005
2016	43558
2017	43906
2018	42073
2019	43878
2021	60666
2022	63046