Year	Number of
1990	201.12
1991	203.7
1992	206.35
1993	208.1
1994	209.75
1995	219.69
1996	232.63
1997	254.29
1998	268.11
1999	276.16
2000	282.82
2001	290.85
2002	297.55
2003	309.63
2004	319.57
2005	332.77
2006	343.17
2007	353.86
2008	364.67
2009	377.43
2010	382.6
2011	389.88
2012	400.21
2013	408.32
2014	411.87
2015	432.13
2016	448.99