Year	Number of
1990	146.58
1991	153.78
1992	161
1993	169.34
1994	180.79
1995	186.68
1996	186.53
1997	186.45
1998	191.32
1999	193.97
2000	193.54
2001	197.29
2002	201.03
2003	198.45
2004	199.04
2005	199.16
2006	206.03
2007	210.67
2008	213.65
2009	219.41
2010	224.62
2011	229.47
2012	236.46
2013	242.69
2014	247.99
2015	254.57
2016	261.02