Year	Number of
1990	351.89
1991	379.4
1992	377.62
1993	385.08
1994	429.78
1995	427.94
1996	389.82
1997	332.49
1998	315.72
1999	332.25
2000	340.59
2001	341.56
2002	352.45
2003	362.25
2004	382.42
2005	416.25
2006	422.27
2007	432.94
2008	440.67
2009	453.21
2010	473.33
2011	439
2012	449.75
2013	437.6
2014	462.05
2015	481.21
2016	485.5