Year	Number of
1990	104.27
1991	108.34
1992	112.89
1993	117.98
1994	123.02
1995	128.53
1996	132.44
1997	139.5
1998	145.89
1999	152.23
2000	158.54
2001	164.22
2002	169.78
2003	175.78
2004	181.76
2005	187.35
2006	194.43
2007	203
2008	210.62
2009	218.37
2010	226.16
2011	238.07
2012	249.84
2013	260.43
2014	271.45
2015	284.53
2016	297.86