Year	Number
2000	24000
2001	27000
2002	29000
2003	30000
2004	31000
2005	32000
2006	31000
2007	30000
2008	29000
2009	28000
2010	28000
2011	27000
2012	26000
2013	26000
2014	25000
2015	25000
2016	24000
2017	23000
2018	23000
2019	22000
2020	22000