Year	Number of
1990	221.84
1991	233.4
1992	244.5
1993	256.53
1994	269.44
1995	283.67
1996	298.31
1997	313.3
1998	330.62
1999	348.07
2000	363.5
2001	381.95
2002	405.65
2003	432.24
2004	462.29
2005	496.9
2006	520.2
2007	546.21
2008	572.31
2009	601.56
2010	642.92
2011	651.51
2012	672.35
2013	692.8
2014	723.9
2015	767.5
2016	817.36