Year	Number
2000	20000
2001	20000
2002	20000
2003	20000
2004	19000
2005	19000
2006	19000
2007	18000
2008	18000
2009	17000
2010	17000
2011	17000
2012	16000
2013	16000
2014	15000
2015	15000
2016	15000
2017	15000
2018	15000
2019	15000
2020	14000