Year	Number
2000	2400
2001	2300
2002	2300
2003	2400
2004	2400
2005	2400
2006	2500
2007	2500
2008	2400
2009	2500
2010	2600
2011	2500
2012	2500
2013	2400
2014	2300
2015	2300
2016	2200
2017	2100
2018	2200
2019	2100
2020	2200