Year	Number of
1990	298.46
1991	303.56
1992	310.03
1993	300.23
1994	302.25
1995	311.04
1996	315.46
1997	322.32
1998	315.5
1999	325.42
2000	341.78
2001	370.1
2002	392.69
2003	413.52
2004	433
2005	458.36
2006	481.52
2007	515.15
2008	543.85
2009	576.42
2010	610.66
2011	625.5
2012	638.35
2013	641.04
2014	643.38
2015	649.91
2016	659.92