Year	Number
1998	52974
1999	56723
2000	71307
2001	85499
2002	110578
2003	124761
2004	142587
2005	198789
2006	237777
2007	302715
2008	360991
2009	398436
2010	479762
2011	586644
2012	725193
2013	739377
2014	643012
2015	633154
2016	733698
2017	717306