Year	Number of
1990	1635.32
1991	1626.98
1992	1615.04
1993	1596.74
1994	1588.52
1995	1581.72
1996	1581.42
1997	1573.74
1998	1572.87
1999	1579.66
2000	1575.92
2001	1581.09
2002	1595.21
2003	1607.42
2004	1622.57
2005	1631.27
2006	1633.87
2007	1661.83
2008	1665.75
2009	1681.3
2010	1706.21
2011	1715.92
2012	1729.36
2013	1737.68
2014	1733.54
2015	1753.33
2016	1772.14