Year	Number of
1990	460.88
1991	498.61
1992	463.97
1993	495.24
1994	554.09
1995	572.42
1996	544.93
1997	461.2
1998	430.88
1999	454.23
2000	468.01
2001	471.52
2002	481.35
2003	492.72
2004	478.85
2005	517.25
2006	526.84
2007	526.65
2008	525.96
2009	522.49
2010	534.24
2011	472.38
2012	483.47
2013	467.75
2014	495.69
2015	515.64
2016	511.98