Year	Number of
1990	154.96
1991	154.15
1992	155.06
1993	155.65
1994	157.45
1995	160.24
1996	164.88
1997	166.63
1998	174.87
1999	181.7
2000	187.43
2001	186.45
2002	187.95
2003	196.18
2004	205.63
2005	214.85
2006	226.99
2007	238.25
2008	247.8
2009	259.56
2010	270.51
2011	282.08
2012	300.49
2013	319.25
2014	339.33
2015	359.13
2016	376.13