Year	Number of
1990	1522.21
1991	1531.37
1992	1551.54
1993	1565.46
1994	1570.19
1995	1580.2
1996	1588.93
1997	1585.81
1998	1572.37
1999	1559.77
2000	1560.99
2001	1558.39
2002	1560.63
2003	1571.52
2004	1564.54
2005	1573.97
2006	1573.24
2007	1567.94
2008	1566.59
2009	1583.67
2010	1566.39
2011	1570.39
2012	1589.22
2013	1587.5
2014	1581.2
2015	1595.1
2016	1612.54