Year	Number
1971	349829
1999	481327
2002	438144
2003	443783
2004	473463
2005	409871
2006	411961
2007	405910
2009	355155
2010	365684
2011	379383
2012	435469
2014	536271
2015	600028
2016	594094
2017	536900
2018	704537