Year	Number of
1990	471
1991	454.17
1992	448.44
1993	446.06
1994	444.47
1995	440.92
1996	432.65
1997	418.9
1998	413.84
1999	414.11
2000	410.74
2001	418.41
2002	420.34
2003	425.78
2004	426.37
2005	427.48
2006	428.43
2007	428.75
2008	435.07
2009	433.38
2010	432.18
2011	437.74
2012	440.19
2013	442.43
2014	443.71
2015	446.49
2016	452.08