Year	Number of
1990	228.45
1991	231.36
1992	236.57
1993	246.88
1994	254.95
1995	266.68
1996	266.72
1997	270.61
1998	275.03
1999	273.61
2000	279.41
2001	283.95
2002	288.04
2003	292
2004	302.93
2005	315.48
2006	318.84
2007	317.94
2008	321.73
2009	335.89
2010	341.92
2011	357.18
2012	368.8
2013	386.05
2014	396.48
2015	410.11
2016	425.07