Year	Number of
1990	229.33
1991	231.68
1992	234.84
1993	245.36
1994	256.4
1995	268.36
1996	269.66
1997	275.1
1998	282.29
1999	291.81
2000	298.89
2001	310.63
2002	322.43
2003	336.75
2004	347.14
2005	359.81
2006	380.32
2007	373.77
2008	382.92
2009	406.09
2010	419.68
2011	433.74
2012	431.06
2013	433.26
2014	437
2015	441.94
2016	454.29