Year	Number of
1990	401.54
1991	405.79
1992	411.06
1993	410.41
1994	412.47
1995	416.47
1996	416.18
1997	417.03
1998	411.45
1999	402.63
2000	399.17
2001	399.99
2002	398.36
2003	401.1
2004	396.83
2005	391.91
2006	385.55
2007	382.83
2008	383.11
2009	386.36
2010	393.06
2011	402.39
2012	414.87
2013	422.75
2014	434.74
2015	449.95
2016	465.78