Year	Number of
1990	424.22
1991	433.2
1992	454.53
1993	473.84
1994	503.72
1995	526.19
1996	537.75
1997	557.18
1998	581.46
1999	573.64
2000	557.49
2001	528.11
2002	506.15
2003	512.52
2004	507.92
2005	508.23
2006	511.68
2007	519.75
2008	526.92
2009	539.12
2010	544.35
2011	553.46
2012	564.82
2013	587.37
2014	602.96
2015	616.82
2016	627.45