Year	Number of
1990	438.35
1991	442.64
1992	456.68
1993	494.49
1994	513.25
1995	470.49
1996	407.7
1997	386.4
1998	394.48
1999	365.48
2000	354.73
2001	367.81
2002	359.36
2003	348.88
2004	345.66
2005	359.16
2006	365.21
2007	353.92
2008	328.82
2009	306.73
2010	301.19
2011	288.74
2012	287.54
2013	280.81
2014	274.4
2015	273.64
2016	273.34