Year	Number of
1990	164.64
1991	173.27
1992	183.94
1993	192.44
1994	207.68
1995	220.9
1996	229.31
1997	237.57
1998	239.25
1999	249.56
2000	250.67
2001	255.57
2002	264.55
2003	264.18
2004	262.32
2005	265.01
2006	268.06
2007	276.59
2008	275.33
2009	283.1
2010	292.4
2011	300.73
2012	307.14
2013	312.66
2014	318.85
2015	325.24
2016	336.82