Year	Number
2000	17000
2001	19000
2002	20000
2003	22000
2004	23000
2005	24000
2006	24000
2007	24000
2008	25000
2009	24000
2010	24000
2011	22000
2012	21000
2013	19000
2014	17000
2015	16000
2016	15000
2017	14000
2018	14000
2019	14000
2020	14000