Year	Number of
1990	312.88
1991	325.93
1992	340.05
1993	355.4
1994	371.24
1995	387.54
1996	397.28
1997	407
1998	417.64
1999	428.63
2000	440.13
2001	443.96
2002	447.53
2003	450.93
2004	455.32
2005	461.66
2006	477.31
2007	494.22
2008	514.26
2009	533.42
2010	551.8
2011	573.88
2012	597.14
2013	622.5
2014	649.42
2015	677.9
2016	709.09