Year	Number of
1990	139.39
1991	151.18
1992	163.23
1993	174.09
1994	188.49
1995	202.33
1996	213.65
1997	222.7
1998	231.87
1999	236.84
2000	239.09
2001	241.01
2002	241.31
2003	246.13
2004	243.95
2005	245.53
2006	249.27
2007	251.49
2008	254.58
2009	259.48
2010	264.14
2011	269.67
2012	274.38
2013	279.96
2014	284.73
2015	292.72
2016	304.27