Year	Number of
1990	319.69
1991	329.57
1992	343.56
1993	347.66
1994	346.96
1995	335.19
1996	320.07
1997	319.01
1998	326.4
1999	326.56
2000	338.03
2001	341.73
2002	347.74
2003	359.39
2004	363.84
2005	374.83
2006	398.31
2007	420.08
2008	442.58
2009	455.04
2010	465.24
2011	484.47
2012	509.11
2013	525.33
2014	553.75
2015	578.33
2016	601.25