Year	Number of
1990	549.11
1991	539.85
1992	530.54
1993	522.2
1994	500.2
1995	485.77
1996	472.98
1997	461.18
1998	449.45
1999	442.22
2000	426.83
2001	426.96
2002	411.6
2003	396.85
2004	379.07
2005	369.13
2006	356.78
2007	356.39
2008	348.87
2009	342.91
2010	350.49
2011	357.59
2012	357.8
2013	361.28
2014	361.38
2015	369.6
2016	377.61