Year	Number of
1990	195.22
1991	201.85
1992	209.15
1993	216.95
1994	225.15
1995	233.86
1996	237.74
1997	241.95
1998	246.49
1999	251.51
2000	257.2
2001	258.56
2002	260.49
2003	262.89
2004	265.65
2005	268.96
2006	273.72
2007	278.75
2008	284.58
2009	290.89
2010	297.89
2011	304.24
2012	311.15
2013	318.46
2014	326.43
2015	335.15
2016	343.47