Year	Number of
1990	162.07
1991	165.77
1992	170.82
1993	176.74
1994	185.07
1995	197.65
1996	210.27
1997	225.6
1998	245.53
1999	265.96
2000	288.12
2001	302.12
2002	313.92
2003	319.16
2004	314.44
2005	300
2006	292.84
2007	289.15
2008	285.99
2009	279.92
2010	280.69
2011	284.12
2012	297.06
2013	303.03
2014	315.4
2015	329.73
2016	345.43