Year	Number of
1990	361.71
1991	374.73
1992	388.88
1993	404.12
1994	420.56
1995	438.63
1996	444.68
1997	452.03
1998	460.55
1999	470.21
2000	481.37
2001	483.8
2002	487.74
2003	492.57
2004	497.93
2005	504.02
2006	514.1
2007	524.35
2008	535.67
2009	547.94
2010	561.59
2011	574.57
2012	589.04
2013	604.44
2014	620.85
2015	638.22
2016	655.88