Year	Number of
1990	456.71
1991	436.23
1992	388.14
1993	358.06
1994	337.81
1995	337.3
1996	329.67
1997	324.99
1998	319.09
1999	312.77
2000	316.25
2001	323.32
2002	334.22
2003	332.7
2004	331.31
2005	343.13
2006	351.29
2007	357.91
2008	366.32
2009	370.6
2010	375.32
2011	370.13
2012	365.22
2013	362.34
2014	360.02
2015	360.07
2016	361.43