Year	Number
1971	230879
1972	250906
1973	273988
1974	301096
1975	338400
1976	368655
1977	395621
1978	424538
1979	453546
1980	463798
1981	468975
1982	464923
1983	459611
1984	453369
1985	454061
1986	450367
1987	455738
1988	458444
1996	473817
2001	490039
2002	488537
2003	487218
2004	492779
2005	498354
2006	500708
2007	510284
2008	513787
2009	511872
2010	508269
2011	486817
2012	486942
2013	439093
2014	415971
2015	393952
2016	371900
2017	357158
2018	349086
2019	341388
2020	342554
2021	343478
2022	338959