Year	Number of
1990	145.83
1991	156.75
1992	166.07
1993	180.51
1994	201.81
1995	215.19
1996	230.91
1997	260.04
1998	292.93
1999	328.7
2000	361.96
2001	395.87
2002	428.88
2003	460.6
2004	490.96
2005	518.12
2006	542.49
2007	559.06
2008	581.17
2009	600.46
2010	611.3
2011	629.53
2012	650.25
2013	668.81
2014	684.11
2015	711.05
2016	734.53