Year	Number
2000	19000
2001	18000
2002	17000
2003	16000
2004	15000
2005	14000
2006	14000
2007	13000
2008	13000
2009	13000
2010	13000
2011	12000
2012	12000
2013	12000
2014	12000
2015	12000
2016	12000
2017	12000
2018	12000
2019	12000
2020	12000