Year	Number
2000	19000
2001	18000
2002	18000
2003	15000
2004	16000
2005	15000
2006	15000
2007	14000
2008	14000
2009	13000
2010	12000
2011	12000
2012	11000
2013	11000
2014	10000
2015	10000
2016	9500
2017	9200
2018	8200
2019	7900
2020	8100