Year	Number
2000	19000
2001	18000
2002	17000
2003	17000
2004	17000
2005	16000
2006	16000
2007	15000
2008	15000
2009	13000
2010	13000
2011	12000
2012	11000
2013	10000
2014	10000
2015	10000
2016	10000
2017	10000
2018	9800
2019	9800
2020	7900