Year	Number of
1990	172.61
1991	176.49
1992	180.87
1993	191.33
1994	203.24
1995	211.63
1996	216.44
1997	219.12
1998	235.07
1999	239.36
2000	245.25
2001	253.99
2002	262.44
2003	276.66
2004	289.12
2005	299.35
2006	310.1
2007	317.59
2008	326.65
2009	334.01
2010	341.24
2011	349.67
2012	360.01
2013	371.98
2014	383.83
2015	396.73
2016	409.82