Year	Number of
1990	365.64
1991	390.49
1992	386.09
1993	417.96
1994	433.76
1995	437
1996	422.07
1997	409.51
1998	426.93
1999	425.2
2000	423.76
2001	447.99
2002	442
2003	461.78
2004	460.74
2005	485.74
2006	499.21
2007	514.56
2008	523.31
2009	477.32
2010	482.39
2011	481.57
2012	469.27
2013	465.87
2014	441.32
2015	448.53
2016	448.93