Year	Number of
1990	129.39
1991	131.49
1992	132.39
1993	137.04
1994	141.68
1995	146.83
1996	152.41
1997	159.08
1998	165.76
1999	170.1
2000	172.78
2001	176.05
2002	179.04
2003	181.49
2004	182.47
2005	182.22
2006	183.96
2007	191.29
2008	201.63
2009	209.83
2010	212.96
2011	208.87
2012	207.79
2013	206.32
2014	206.27
2015	207.22
2016	209.65